Virtual Reality Based Application for Safety Training at Shipyards

The implementation of safety training is conducted to provide knowledge on the importance of safety for its employees. However, the implementation of safety training requires many consumable things such as a lot of Portable Fire Extinguishers (PFE) that increase the operational cost and trigger the environmental pollution. This research aims to design a safety simulation based on VR (virtual reality) to provide an immersive experience for safety training and reduce the training costs. It was obtained that the application of VR technology requires two main devices namely HMD (Head-Mounted Display) and controller. Observations were conducted in the training of conventional safety and health at shipyards and training institutes. This research only simulates training on the use of PFE, fire drill, and risk observation on confined space from the ten topics of safety training based on observations that have been undertaken. Software such as Inventor, Microsoft Visual Studio, and Unity were used. After safety simulations was conducted, the result showed that safety training used VR can improve the work safety theory knowledge by 14.05%. Total cost of investment required for the development and equipment was IDR 24,043,667. The reduced cost of the safety training using VR was about IDR 193,889,154.88 or 68.13%.

INTRODUCTION
SHIPYARDS are business entity that has a high risk of workplace accidents. Manpower Social Security Administering Agency of Indonesia records the number of occupational accidents in Indonesia tends to continue to increase. A total of 123,000 cases of occupational accidents were recorded throughout 2017. This amount increased by 20 percent from 2016. The majority of causes of occupational accidents occur because of unsafe actions (unsafe action) of workers. Unsafe action that workers often do, causing 80% of the work accident is not obedient in the use of PPE, the lack of understanding the work SOP, the unkind work, and disparage the dangers of the environment [1].
To reduce the number of occupational accidents in shipyards and increase worker knowledge of the risk of hazards faced, the shipyard conducts in-house occupational safety training such as Basic Fire Fighting, Fire Drill, operational tool lift and transport, work permits etc. But unfortunately, it is ineffective because the workers have never felt the accident until the accident happened. Moreover, the In order to answer these problems, the main objective of this research is developing a safety simulation based on VR (virtual reality) to provide an immersive experience for safety training and reduce the training costs. it takes a simulation of occupational safety and health, which is based on virtual reality technology. It is conducted to provide an immersive experience in training and cut training costs. Simulating a virtual reality-based computer programming will provide an experience directly to workers in cases of work accidents that are very common in the shipyard. The procurement of this simulation tool in the shipyard is expected to reduce the working accident rate and reduce air pollution and pollution caused by occupational safety training.
The novel components of this research are twofold. Firstly, VR has never been used to model a safety training for ship production and ship repair and maintenance in shipyard. Secondly, this research provide research analysis based on cost and technical aspect on using virtual reality for safety training in shipyard.

Virtual Reality Technology
Virtual reality technology is a technology that allows users to interact with a computer-simulated environment in both the real world and the imaginary world [2]. Virtual reality is a partial or complete representation of a tangible or fictionalized electronic environment. Such representations may include a three-dimensional image or an image that has an interactive nature and allows the user to be in the environment in an immersive manner [3].

2.1.1.
Virtual Reality Hardware and Supporting Software The adoption of virtual reality technology requires Head-Mounted Display hardware assistance and a controller to allow users to experience immersive and interactive experiences. The current virtual reality devices are as follows: -

Blender
Blender is a 3D software used to create visual effects, 3D prints models, interactive 3D applications, and video games. Blender has several features including 3D modeling, texturing, bitmap image editing, and rendering [6].

Unity Game Engine
Game Engine Unity is a three-dimensional game authoring tool for MAC and personal computers. Game engine is the core of every video game. From translating to displaying graphics on screen, integrating controls and devices for games, and game engines will make the next decision that will happen. Modern three-dimensional Game engine full of written code [7]. Training using virtual reality technology can be divided into three categories. The first category is training from fields that require a virtual environment similar to a real job situation. The training included training in driving vehicles, trials, maintenance simulators, and medical and military procedures. The second category of training presents aspects that cannot be brought to the real world to support learning. Examples of this category include prehistoric site visualization, nuclear industry, and fire extinguisher. The third category presents activities that are not purely training situations, but involve cognitive activities requiring a number of implicit learning actions [8].
Currently, some occupational safety training uses virtual reality technology as one of the entire teaching equipment. Such as the Warsaw-based VRSENSE Training Institute and training organized by government agencies such as the British Safety Council which provides a wide range of certification for one of the safety and health certifications Work.
VRSENSE's occupational safety and health training focuses on virtual reality-based training. This agency sells virtual reality simulated application products in the form of compact disks and virtual reality appliances supporting simulated applications that they develop.
General Safety Hazards 4.
Construction Safety Hazards The work safety and health training simulation application developed by VRSENSE can only be run on HTC Vive hardware.
British Safety Council also developed several virtual reality-based certifications, one of which is occupational safety and health certification. In addition to the cyber reality-based occupational safety certifications the British Safety Council also organizes online certifications and classes. Occupational safety and health certifications with virtual reality devices are as follows.
National General Occupational Safety and Health Certification by NEBOSH The certification organized by the British Safety Council uses Oculus Go hardware as a certification teaching device.

Shipyard Safety and Health Training
Occupational Safety and Health training is distinguished by its organizational level. The training is provided for management, supervisory personnel, and worker levels. Work safety training for workers is done at inhouse before being allowed to start work. Shipyards must ensure that no worker is assigned to do high-risk work unless already given the necessary training [9].
The in-house workplace safety training topic that the shipyard needs to do is as follows.
-General problems of occupational safety and health, policies, rules and regulations.
-Identification of hazards and risk assessments.
-Safe working procedures including during emergencies.
-Permit to work, isolation, gas free, enter confined space, emergency response.
-Company-specific methods and procedures such as the use of safe workshop machines. -General topics such as self-protection, scaffold, slip, fall from altitude.
-Briefing before carrying out the task to highlight the dangers and methods to deal with it.
-Demonstration of certain tasks.
-Development of surveillance skills.
-Exercises and training.

RESEARCH METHODS
Procedure for conducting this research is illustrated in Figure 1.

. Application Development
Application development began after the simulation concept was obtained based on the results of data processing. Then simulated occupational safety using virtual reality designed computer-based programming.
Here were the stages of application creation.
-Three-dimensional environment creation -Application Script Creation -Application development using game Engine software

Application Validation
Application validation needed to be conducted to find out if the developed application can be used by the user properly. Application validation was performed by observing the movements performed by the user with the reaction displayed on the Head-Mounted Display (HMD) used by the user. Application validation was conducted against the controller's movement input and user head movement against the view in HMD.

Analysis and Discussion
Technical analysis conducted in this study included a comparison of user experience in occupational safety training using VR to conventional occupational safety training. Other technical analysis was to compare pre-Test and protest results in writing to trainees before and after the use of job safety simulations using VR to determine the effect of safety training work of participant safety theory knowledge. At this stage, an economic analysis of the application design simulation of the virtual reality-based work safety training was conducted. Economic analysis conducted in the form of estimation of investment costs in application development and comparison of conventional employment safety training costs with work safety training using virtual reality devices.

CURRENT WORKPLACE SAFETY TRAINING
According to ministerial Regulation No. 26 of 2014 on assessment of implementation of occupational safety and health management system of the company who employ at least one hundred workers and have a high level of potential danger the company was obliged implementing occupational safety and health management systems.
One of the systems was to provide training in the form of inhouse training. Inhouse training was given periodically every month once and every new project that has a certain risk of security was also mandatory inhouse training. Besides inhouse training, it was also done toolbox meeting every morning before doing the job. Occupational safety and health training in shipyards was coordinated and performed by the Health Safety and Environment division [10].

Implementation of Occupational Safety Training
In the implementation of occupational safety and health training, each class session consisted of 30 participants and the material will be delivered by one teacher and one teaching assistant for lecture activities, class discussions, and questions and answers.  2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4  7 House Keeping/5R 8 Fire Prevention and Protection 9 APD 10 Permit to Work 11 Tool and Equipment 12 Power and Electrical (Source: PT.PAL, 2019) Table 1 explained about the work safety training materials conducted in the shipyard PT. PAL Indonesia was performed routinely every month.

Personal Protective Equipment
Potential work accidents that can be minimized when using personal protective equipment including sharp objects, falling objects, sparks, and splashes of harmful chemicals. Certain occupations have their own risks, so it was necessary to use special personal protective equipment.

Basic Fire Fighting
Early prevention and response to fire hazards was required to prevent fire incidents and reduce the impact. In extinguishing the fire, the substance used must be precisely according to the class of the fire due to different flame characteristics [11]. Substances that correspond to the fire class can be seen in Table 2 below.  Table 2 showed the appropriate fire extinguisher was used for its fire class according to the National Fire Prevention Association.

Response to Emergencies
Emergencies were a condition, abnormal conditions or events where these circumstances occurred suddenly and can be transformed into disasters resulting in many casualties and damages. The step in the evacuation was as follows.
a. Keep calm and do not panic. b. Use the emergency ladder. c. Regular walk and do not run. d. It does not carry large items and complicate evacuation. e. Tell colleagues around the room to evacuate with others. f. When stuck with fire smoke, stick to the emergency stairs by taking a short breath, try to crawl or crawl to avoid smoke, and do not turn around because it will collide with the person behind. g. If you are forced to break through the smoke then breathe and fast to the emergency exit.

Risk Observation
The risk observation training aimed to find or know the risks that may arise in activities undertaken by companies or individuals. In the prototype developed this time, the user will observe the risks in the confined space. Ordinances for entering confined spaces were as follows.
a. All channels, including disposal channels connected with limited space, must be inspected in accordance with the possibility of danger. Make sure that the entire drain is closed or isolated. b. Only secured portable lamps or chandeliers that do not cause power jumps that can be worn in confined space areas. Ordinary incandescent lamps are very dangerous to use because of sparks from the switch or the exposure of hot filament from the lamp against flammable materials then it will be able to ignite and explode. c. Each worker must read the ordinance of entering the confined space and ask for the supervisor's permission and must wear all necessary personal protective equipment. d. Before opening the manhole cover, the surrounding air condition should be monitored to ensure that the oxygen content in the safe level is 19.5%-23.5% and flammable gases should not exceed the safe exposure for health. e. All areas of confined space must be increased by the concentration of toxic gases, oxygen levels, and explosive potential by experienced operators in testing equipment before they are allowed. f. Supervisors must ensure that limited space is safe to enter. g. Any worker who will enter the confined space must receive an explanation near the confined space called the Tailboard Briefing.

SAFETY TRAINING PROTOTYPE DEVELOPMENT
Workplace safety training simulations using cyber-reality technology were designed to be able to provide simulated work safety training based on work in the shipyard. Due to limited cost and timing of authors, the prototype developed in this study only simulates training on the use of PPE, fire drill, and observation of risk in confined spaces. These three trainings were also based on categories compiled under the journals of Virtual Reality for Training and Lifelong Learning. The category was a simulated tutorial in the training of the use of the fire extinguishers, a simulated emergency response in the simulation of Firedrill, and the observation of the risk that took the case of work in confined spaces. This VR-based training also came with material about general occupational safety such as the introduction of personal protective equipment, Basic Fire Fighting, Emergency response Plan, and Risk Observation in the form of video.

Tutorial
In the simulation, the tutorial will be designed to accommodate the training of the use of light fire extinguishers.

Response to Emergencies
A hazard response was designed to provide participant experienced in a fire hazard and provided an interaction room for participants ' response in the danger of immortality.

Risk Observation
While the observation training risk provided knowledge in observing the risk of danger in confined spaces.

Devices Uses for Occupational Safety Training
In this research, the VR hardware used was Oculus Go with the following specifications.  Table 3 explained that Oculus Go has sufficient specifications to provide a simulation with the help of HMD and its default controllers. Although there was a deficiency in his freedom degree thus it cannot be simulated the movement of walking and bent.

Development of Safety Training Application
Prototype Work safety training simulation using virtual reality consists of the preparation stage of teaching materials, application development, and test stage applications [12]. The plot of prototype work safety training simulation in this study can be seen in Figure 2. Explanation of the development flow of safety simulation prototype is explained as below.

Determining Teaching Materials
In this study, the teaching materials to be taught with cyber-reality technology was the safety of work on shipyards. The materials to be taught in this application are tutorials in the use of fire extinguishers, response in danger of fires, and observation of hazard risk in confined spaces.

Determining Which Content Can Be Simulated
From the material, the matrix was created to determine the training process that can be simulated with VR. The process of determination was based on the action during training that can be simulated with VR with media controller and HMD as a device of interaction with the virtual world.

Defining the Sub step of any Material
The creation of a sub step of each training material was useful to create an application programming framework to be developed. The sub step of each training material covers the conditions of the virtual environment in the training, the equipment to be used in training, the mechanical interaction of equipment in the training, and the orders that can be done in the training.

5.3.4
Defines VR Devices The VR device used in this study was Oculus Go with the Android platform to run the application.

Creating Virtual Environments
The initial stage of creating a safety simulation prototype using VR was the creation of an environment or virtual environment that visualized the real environment in each training simulation category.

Script Writing
Application script writing was created for any object objects in the virtual environment in order to interact with the desired form of interaction. Application script writing was created using Microsoft Visual Studio software.

Application Development
At this stage, all the objects that have been created were put together with a script containing an interaction command using an engine game software called Unity. This stage was an important process in the development of a simulator software, if at the time of the execution of the object cannot be manipulated according to the instructed then it is likely there is an error in the script/code that has been created.

Application Testing
Application testing was performed to see if there is any use in application. At this stage, a user interface response validation test and a command function in the simulation of the controller and HMD movements when using the user. The invention of the problem in this stage will be done improvements to the Unity software. After that, the

Safety Training Simulation User Interfaces
The user interface on the virtual reality-based work safety simulation consisted of home menus and training categories such as the use of extinguishers, fire drill, and observation of risk in confined spaces. Figure 3 was a user interface of home menu simulation training. User can choose freely the type of work safety training that is desired in this section.
The User interface in work safety training can be seen in Figure 4. Figure 4 was the user interface of one of the trainings that is fire drill. In the training session, the user has begun to calculate the training and assessment time and at the end of the simulation, the training was displayed as it has been done and what should be done.

Technical Analysis
Technical analysis conducted in this study included a comparison of user experience in occupational safety training using VR to conventional occupational safety training. Other technical analysis is to do comparisons of pre-test results and pro-test trainees before and after the use of simulated work safety using VR.

Variable
Conventional Training Training with VR

Safety
Involving a genuine environment that has a high risk of accidents Training is conducted in an environment with a high level of safety

Environmental Impacts
Involving fires that cause smoke and fire extinguishing substances that cause environmental pollution Training does not cause pollution and pollution

Time
Involving time for preparation Training does not take a long time to prepare and can be done repeatedly

Equipment
Involving equipment that materials

Simulation
Conventional training has limited media to visualize occupational safety and health material Training has a high level of engagement

Assessment
Done manually Done automatically Table 4 is a comparison of the two training processes based on seven variables: space, safety, environmental impact, time, equipment, simulation, and assessment.
The results of pre-test and post-test have been done by the five respondents in writing, obtained the average result of the correct answer from pre-test is 21.8 of 30 questions. Post-test that was completed by the five respondents were obtained the average result of the correct answer from post-test is 25.4 of 30 questions. Thus, an average increase of 14.05% was obtained. It can be said that VR-based occupational safety training can improve participants ' occupational safety theory knowledge by as much as 14.05%.

Economic Analysis
Economic analysis was conducted to see the cost comparison between conventional occupational safety training and VR-based occupational safety training [13]. The stage that will be calculated is the investment cost of a set of VRS based safety training simulator tools, operational cost of occupational safety training using VR, and the comparison of conventional job safety training costs to Work-based safety training.

Equipment's Investment Cost
3D Artist with 64 hours' worth of IDR 2,453,333.33 and Application Developer with 140 hours' worth of IDR 9,095,333.33 to total application of Rp. 11,548,666.67 and investment cost of a set of training equipment of Rp 12,496,000. The details of the prototype development costs in this study can be seen in Table 5.  [14]. While for VRbased work safety training requires the cost of application designing, VR equipment, and electricity. The details of the cost comparison can be seen in Table 6.  Table 6 indicates that there is a reduction after the use of VR devices for occupational safety training of IDR 193,889,154.00. It can be concluded that occupational safety training using VR can reduce costs by 68.13% of conventional training.

Prototype Validation Testing
The application validation test in this study needs to be done to find out if a work safety training simulation application is developed can be used properly. Thus, validation is the direction of view and controller gestures to match the movement of view direction and controller in the virtual environment. In the validation phase, this application is done by comparing the display of HMD and controller with the movements performed by the user, while for movement in the virtual environment cannot be performed validation because of movement in the environment Virtual was conducted with a touch on the trackpad by the user, plus in this training simulation the user does not make migrations in the real world. Validation was conducted using simulation view of fire drill training because there is an evacuation route that has an angle 90 ⁰ and to match it with user movement used 360 coordinates ⁰ thus this validation can be done Accurate. The simulation view of fire drill can be seen in Figure 5.  User will move HMD by looking towards the bottom, top, front, left, and right. During the move make sure that the display in the application corresponds to the user's head movement. The second validation is performed with the user directing the controller towards the bottom, top, front, left, and right. During the move make sure that the display in the application corresponds to the direction of the user controller.

Prototype Verification Testing
This study used the questionnaire method to verify the Work Safety training simulation application in this study using the questionnaire method. The questionnaire aimed to provide an assessment of the feasibility of the application that has been developed. The respondents were workers in shipyards because the application was developed to be implemented in shipyards. Questionnaires consisted of several questions about developed applications. Respondents first conducted a training simulation using developed applications and then carried out the filling questionnaire. Questions in the questionnaire used the Likert-interval scale one for the lowest and four values for the highest score.
Based on the results of a processed questionnaire, the highest average percentage is gained on the fourth question, means that simulated occupational safety training using virtual reality devices is more environmentally friendly than Work safety training conventionally with an average percentage of 90% which means 90% of respondents strongly agree that developed applications are assessed more environmentally friendly. Meanwhile, the fifth question, which is a practical safety training simulation is used to get the lowest percentage of 70% but still in the third interval, which means 70% of the respondents agreed that the developed open is practical to use. From total percentage, the average obtained value of 83% entered at the fourth interval which means that the average respondent strongly agrees with the developed application safety training simulation in this research.

CONCLUSION/SUMMARY
After the experiment and research the conclusion of the study is as follows: 1) The process of supply of occupational safety and Health to the shipyard is currently carried out in-house and external training or training that requires outside parties. In-house safety training includes general recognition of occupational safety, hazard observation and risk assessment, supervision skills development, work procedures, work permit, isolation, gas free, entering confined spaces, of emergency response, use of safe equipment, scaffolding, work at height, demonstrations such as fire suppression and the use of personal protective equipment and exercises as well as training such as fire drill, earthquake drill, and tsunami drill. The implementation of occupational safety training in shipyards has high levels of danger such as fire involvement and scaffold use in altitude. 2) Designing a virtual reality-based work safety simulation application on a shipyard requires two supporting devices namely the Head-Mounted Display and a controller. The design of a work safety simulation application based on cyber reality technology is done through several processes that define teaching materials, determine materials that can be simulated with VR devices, determine the substeps of any material, determine which VR devices to use, create virtual environments, application script writing, app development, and app testing. The study only simulates training on the use of extinguishers, fire drill, and observation of risk on the limited space of ten occupational safety training topics in shipyards. 3) A comparison of conventional occupational safety training with work-based safety training in virtual reality technology is seen from the seven variables in the training process: space, safety, environment, time, equipment, simulation, and assessment. VR-based work safety training simulations can improve the theoretical knowledge of occupational safety trainees as much as 14.05% based on written pre-test and posttest results. The cost required to design a work safety simulation application based on virtual reality technology is divided into the cost of making applications and equipment costs amounting to Rp 24,043,667. The reduced cost in occupational safety training using VR against conventional occupational safety training is Rp 193,889,154.88. Job safety training using VR can reduce occupational safety training costs by 68.13% of conventional job safety training. The limitations of this research is simulated only on the utilization of fire extinguisher, fire drills, and risk observation in confined spaces from the ten topics of in-house work safety training in shipyards. Therefore, the future work, other in-house safety training topics can be simulated. In addition, this research applies virtual reality


Relationships between mental workload, job burnout, and organizational commitment

The business environment has becoming exceptionally unsteady and competitive recently. Information technology advancements and ever changing customer preferences has played a substantial role in an increase of the significance of highly productive, committed and loyal employees. These changes bring both advantages and challenges need to be addressed. The more challenges accelerate, the more issues come up to solve in timely manner. For any organizations, not only taking care of the customers but also employees of the organization should be treated equally taking a better care about their psychological and physical health as well as creating a healthy work environment. The objective of the current research is to study correlations of workload, job burnout and organizational commitment in the case of nurses working in the Health Center of Selenge aimag, Mongolia. According to the results, an increase of mental workload nurses by one unit results in job burnout increases by 0.578 (beta) unit and leads to the decrease of the organizational commitment by 0.437 (beta) unit. Moreover, one-unit increase of job burnout leads to decrease of the organizational commitment by 0.301 (beta) unit.

Introduction
Employee loyalty ensures the organization competitive advantages [1]. Recently technology based businesses like banks and medical institutions are getting more focused on the upgrading employee loyalty, rather than years in service for the organization, bearing in mind their further contribution [2]. Therefore, for maintaining highly productive, loyal and highly committed employees the organizations are more than ever required to address employee physical and psychological health, balanced workload and healthy work environment.
An excessive mental workload, work stress and exhaustion bring negative impacts on employee loyalty as well as organizational outcomes. As a poor performance and productivity due to the job related issues often contributes to the severe damage in employee wellbeing, the scholars and business practitioners pay more attention on the mental workload [3][4].
Specially, evaluation of efficiency and mental workload is essential in a man-machine interacted work environment [5]. The significance of human factor is vital for maintaining high performance in sustainable manner [6]. To reduce unforeseen risks associated with the human activities, it is crucial to evaluate the mental workload of employees in a certain interval of time. The time pressure, multi-tasks, and hastiness not only result in high mental workload but also cause depression and job burnout which negatively impact employee's life.
Researchers provided different studies that identified the relationship between numerous conditions such as intense workload, the job burnout and the employee loyalty to the organization [7][8], mental workload and organizational loyalty [9], mental workload and poor performance [10], decrease of employee loyalty to the organization [11][12][13][14], decrease of job satisfaction [12] and demonstrated how these conditions might have impacted on employee wellbeing and organizational outcomes.

Literature review 2.1 Workload
Workload issues have been studied by various researchers, and they approached differently explaining the source of workload, mechanism and measurement. Gopher and Donchin (1986) described the work load as the interaction between mental needs of employee to perform his assigned tasks. Work quality related workload is the physical and mental challenges the employee experience while performing his work tasks. Workload is identified as the quantitative and qualitative variables [15], or mental and physical variables [16].
Mental Workload: It is important to distinguish between mental and physical workloads [16] as the causes and effects can be different in terms of theory and practice. The concept of mental workload is originated from cognitive load theory that concerns with the relations between human mind and its limitations [17]. By this theory, if a human is over or low loaded, learning new things and performing tasks are influenced negatively [18]. Taking in account this perspective, Hart described the mental workload as the adaptation and interaction between work requirements and employee's perception, talents, abilities and emotions [19]. For instance, two people performing the same tasks may end up with different outcomes. To reveal the reasons serving behind differences the mental workload may be considered and analyzed carefully [20]. Moreover, the amount of information obtained during work tasks is related to mental workload as the ability to memorize the information can affect in balancing between task demand and cognitive resources [21]. Work demand with time pressure, complex in nature increases the workload perception [22].
Vidulich and Tsang considered that mental workload is consisted of exogenous task demands and endogenous supplies of resources. Clearly, task priority, task difficulty, situational contingencies are classified as exogenous task demand while updating, perceiving memory, decision-making, planning and processing are considered as endogenous ones [20]. Mental workload is related with the characteristics of the tasks, employee's skills and abilities and environmental features of the workplace and the organization [22].
Cognitive demands for performing tasks prompt mental workload perception of employees. In this sense, mental workload is considered with the complexity of the tasks that are required to perform for daily activities [22]. Vidulich and Tsang described workload as an interaction between employee's capacity and task requirements [20]. Deviations between structure of the required tasks and human capacities affect the occurrence of the workload. It means imbalance between task demands and employee capacity, mental comes to exist.
Mental workload get attention for being a significant occupational risk factor in the workplace that leads to loss of performance, productivity, welfare and well-being [3,4,23]. Performance failure may increase the perception of the workload [24] and consequently, overload and fatigue speed up making mistakes and failures in the job [25].
On the other hand, when mental workload increases, control variability and errors increase and an individual performance tend to decrease. The workload related with the volume and quantity is considered in relation to the volume of the employee job tasks [26]. The workload is one of the risks in the job that may threaten employee commitment, loyalty, productivity, satisfaction and wellbeing [3][4].

Job Burnout
Job burnout is a concept that is discussed in the organizational behavior literature by Freudenberger and Maslach. Burnout described by these researchers as an overwhelming exhaustion, feelings of frustration, anger, cynicism and a sense of ineffectiveness and failure [8]. Job burnout is a negative phenomenon that is originated from the chronic job stress and causes harms regardless the nature of the occupation [27]. Burnout is an emotional and mental exhaustion that make people stranded [28].
Work overload, conflict with other people in contact often reveal the sign of burnout and it is often visibly demonstrated by loss of trust and negative attitudes towards others. When time passes feeling unhappiness, dissatisfaction about the job accomplishment lead to inability coping with their job and the suffered one evaluates himself, gets aware of the burnout. The main dimensions of job burnout considered as emotional exhaustion, depersonalization and personal accomplishment [29].
Demerouti and colleagues (2001) considered that burnout may be found in any occupational context and seen both within and outside the human services [30]. While in the beginning the theoretical concept development of burnout, it principally discussed work associated factors, however recent researchers consider that environmental and individual factors also have an effect on burn out syndrome [29][30][31][32].
Burnout occurs as a result of complicated interaction between individual characteristics and factors in the work environment [10]. According to some studies causes of burnout with a focus on the work environment indicating role stressors, organizational structures, and job characteristics. Particularly, what is stressful for one may not be stressful for another [29].
Mainly, burnout develops after continues, repeated and unsuccessful confrontation of undesirable working conditions [24]. As Karabay, Tezergil and Köse (2014) considered the reason for the burnout among people work related stress factors [33]. The factors cause the burnout situation at work and create negative circumstances. Moreover, these factors influence the performance of employees and reduce the productivity. According to Maslach (2003) burnout is a response to chronic work related stress that attempts to adapt and protect oneself from it [34].
Emotional exhaustion: The current component is considered as the key symptom of burnout, and it is strongly related with other components. Emotional exhaustion refers to the feelings of being emotionally over extended and exhausted by one's work. It is regarded as a lack of energy and feeling that one's emotional resources are used up. As Maslach (1982) described it as it as a response for the overwhelming emotional demands of other people. Individuals who are emotionally exhausted lack enough energy to face another day, and often report that they are filled with dread at the prospect of returning to work for another day.
Depersonalization: The next component of burnout is depersonalization. Researcher consider it as defensive coping response to deal with the effects of emotional exhaustion when alternative coping resources are not in a place. When the one suffer from burnout often developed a detached, callous or dehumanized responses to the people they should to care for. It also involves the development of negative attitudes and feelings towards persons for whom work is done. It may be expressed as unprofessional comments towards coworkers, blaming others for their problems. Generally, it is a distant attitude towards work.
Diminished personal accomplishment: It is the tendency to negatively evaluate the worth of one's work, feeling insufficient to perform his job, and a generalized poor professional self-esteem. Individuals with burnout syndrome show some symptoms like frustration, anger, fear and anxiety as well as some physical discomfort including insomnia, headache, paroxysm and even digestive track discomfort. Diminished personal accomplishment is a tendency where professional value their own capacity to carry out tasks and to interact with coworkers and feeling dissatisfied with achievements. Often job burnout results from an unpleasant work environment, frequent incident of unfavorable conditions and a long time progressing stress [10] that negatively affects on employee productivity, job satisfaction and encourage employee turnover intention.

Organizational commitment
Organizational commitment can be perceived as the trust built up among the employees. Committed employees possess a sense of obligation to provide a loyal service to the organization in the future as the one feel confident within the organizational climate [35].
Loyal and committed employees are a valuable asset for the organization as they are capable generating significant amount of profit. The employee emotional attachment and connection to the organizational decides if the employee will be committed or not. Employee loyalty and job satisfaction are crucial in the organization's achievements and only committed and satisfied with their job employees are key for maintaining an effective cooperation with the business's main stakeholders. As an employee communication and job satisfaction are contributing to the increase of the commitment, giving a special focus on these issues enable organizations increasing their employee commitment [36].
Meyer and Allen (1991) identified 'three component model of commitment', namely affective commitment, continuance commitment and normative commitment.
Affective Commitment: Affective commitment refers to a strong psychological engagement that make the ones to be loyal to the organizational goals, values and coworkers. If the he or she considers that the organizational goals and values are consistent with personal values, aspirations they tend to become more committed and loyal to the organizations. Numerous factors such as work tasks challenge the employees, clarity of job responsibilities, clarity of goals, management attitude towards to the employees, team unity, equality, respects for individuality, feedback from managers, participation and dependence on others also impact to the employee commitment.
Continuance Commitment: It relates to the degree employee's sense if they need to stay at their organization based on their reflection of costs and benefits of staying or moving to another organization. When an employee feels the need continuing with their present employer because of their wage and fringe benefits would not improve if they move to another organization cause this type of commitment and make them stay with the present employer. Employees with multiple years of experience of working at the same organization or seniority often contribute enjoying multiple benefits and make them stay committed to the organization, however it is not always because of enthusiasm.
Normative Commitment: Normative commitment refers to employee's feeling of obligation to the organization and the belief that continuing their work at the organization is the right thing. Regardless the benefits and job satisfaction the employees remain committed to the organization. High employee commitment can be seen by their devotion to fulfill the organization's goals, improvement of productivity and efficiency and provision of a quality service to the customers.
Employees contribution to the achievement of the organizational goals and objectives are valuable. Only maintaining a favorable work environment, work life balance as well as their wellbeing enable employees to become committed to the organization. Ensuring these factors in sustainable manner require HR managers to understand and research the state of employees' mental workload and job burnout to better recognize how their employees are committed to the organization.
Numerous studies are conducted to realize the relationships between these factors, including the relationships between job burnout and organizational commitment by Brown and his associates (2019), the relationships between psychological condition, organizational commitment and job burnout by Peng and researchers (2013)and correlations between organizational commitment, job burnout, psychological condition and anxiety by Zhou and researchers (2018). Moreover, Lin and researchers (2013) conducted the study on the impact of stress, job burnout, employee satisfaction to the organizational commitment. Also Abbas, Kanwal, & Iqbal (2014) and Usman & Raja (2013) conducted similar studies on the relationships between above said factors.

Research design
Upon reviewing the research designs and results of the above researches conducted earlier we proposed the following research design.

Research hypothesis
We proposed the following hypothesis for the study: H1: Mental workload exposure causes job burnout. H2: Mental workload influences to the organizational commitment. H3: Job burnout influences to the organizational commitment.

Research method
The current survey is conducted to identify if mental workload and job burnout impact on the organizational commitment in the case of nurses working in the Health Center of Selenge aimag. The survey data is processed using SPSS 23.0 and Smart PLS 3.0. The results are produced based on the results of factor analysis, reliability test, correlation and regression analysis and PLS analysis.
Sample: The population of nurses working in the above mentioned medical facility is 175 and selection of 120 nurses for the survey could present the population with 95 % confidence level of probability. The data of 124 questionnaires is considered for the further analysis.  Only 15.3% of the participants of the survey were male and it can be concluded that the majority of the professionals are female. By marital status, majority of nurses are married (83.9%) and only minority (16.1%) are single ones. By age, 51.6% of the respondents were young people who are below 40 years old, 39.5% of them were at their early 50s. Majority of the married professionals had children and only unmarried people tended to have no children.
By work experience, 6.5% of the respondents have up to one-year experience, 3.2 % worked 1-4 years of experience, 41.9% have 5-9 years of work experience, 28.2% of them worked 10-14 years and 20.2% of respondents worked more than 15 years. By type of work, 87.1% engaged in regular day work and 12.9 % of them worked by shifts. By wage size, 47.5% earn up to 900.000 MNT, 28.2 % earn between 900,001-1,100,000 MNT, 12.1% earn 1,100,001-1,300,000 MNT, and 12.1% of them earn 1,300,001-1,500,000 MNT. It shows that the salary level of the medical professionals, particularly nurse's salary is very low.
It is said that 67.7 % of the respondents had a sickly leave within a year due to Covid-19 (33.9%), heart and vascular disease (27.4%) and gastroenterological, joint and muscle diseases (3.2%). It can be concluded that nurse's job is one of the riskiest job among the medical professions.

Reliability test
For verification of the reliability of the questionnaire Cronbach's Alpha value has been checked as it must reach 0.7 [37] and in our case Cronbach's Alpha value for all variables fully reliable for measuring the proposed variables. Moreover, composite reliability coefficient all presented more than 0.  Source: Own processing.
The results of the analysis show that the correlation between mental workload of nurses and organizational commitment have a weak correlation [r = -.370, p< 0.01] while job burnout and organizational commitment presented a visible correlation [r =-.575, p< 0.01].

Structural Equation Modeling
To ensure the reliability of data and evaluation of the model we estimate R-Squared to better predict the structural equation modeling. Through an estimate of relations between movements of a dependent variables based on an independent variables movement we found that the data and predictions unbiased or significance (p <0.05). The results are shown in the following Table 4:  We conclude that all proposed hypothesizes are supported as the beta coefficient of all variables are positive and statistically significant (p <0.05).

Conclusion
Employee commitment ensures the long term organizational sustainability maintaining the prestige, values and organizational culture that is an asset reaching the competitive advantage over competitors. Therefore, for keeping the employee efficiency, commitment, their active participation in organizational life the employers need to give a significance on mental and physical health of employees, balancing the workload and creation of healthy work environment.
The current research is examined the relationships between mental workload, job burnout and organizational commitment. Upon reviewing related theoretical framework and researches on mental workload, job burn syndrome, organizational commitment we proposed hypothesis on the relationships between the above said variables. We developed a questionnaire with Likert 5 scale measurement based on the frameworks and instruments developed earlier such as CarMen-Q developed by Rubio-Valdehita & et al (2017), MBI-HSS instrument by Maslach and Jackson (1981) and OCQ survey Meyer and Allen (1997). We survey is conducted among 124 nurses working for the Health Center of Selenge aimag.
According to the results, the case of the nurses of The Health Center of Selenge aimag show that an increase of mental workload nurses by one unit results in job burnout increases by 0.578 (Beta) unit and leads to the decrease of the organizational commitment by 0.437 (Beta) unit. Moreover, one-unit increase of job burnout leads to decrease of the organizational commitment by 0.301 (Beta) unit. Based on the results of the study we make the following conclusions: 1. Time pressure, multitask handling, urgency and heavy workload often lead to the stress and job burnout which negatively affect one's life [7]. 2. We observed that the greater mental workload, the job burnout increases simultaneously [β=0.578; p<0.00]. In other words, the more people feel more time pressure, stress and cognitive needs they feel exhaustion and job burnout.


robotics A Methodology for Flexible Implementation of Collaborative Robots in Smart Manufacturing Systems

: Small-scale production is relying more and more on personalization and ﬂexibility as an innovation key for success in response to market needs such as diversiﬁcation of consumer preferences and/or greater regulatory pressure. This can be possible thanks to assembly lines dynamically adaptable to new production requirements, easily reconﬁgurable and reprogrammable to any change in the production line. In such new automated production lines, where traditional automation is not applicable, human and robot collaboration can be established, giving birth to a kind of industrial craftsmanship. The idea at the base of this work is to take advantage of collaborative robotics by using the robots as other generic industrial tools. To overcome the need of complex programming, identiﬁed in the literature as one of the main issues preventing cobot diffusion into industrial environments, the paper proposes an approach for simplifying the programming process while still maintaining high ﬂexibility through a pyramidal parametrized approach exploiting cobot collaborative features. An Interactive Reﬁnement Programming procedure is described and validated through a real test case performed as a pilot in the Building Automation department of ABB in Vittuone (Milan, Italy). The key novel ingredients in this approach are a ﬁrst translation phase, carried out by engineers of production processes who convert the sequence of assembly operations into a preliminary code built as a sequence of robot operations, followed by an on-line correction carried out by non-expert users who can interact with the machine to deﬁne the input parameters to make the robotic code runnable. The users in this second step do not need any competence in programming robotic code. Moreover, from an economic point of view, a standardized way of assessing the convenience of the robotic investment is proposed. Both economic and technical results highlight improvements in comparison to the traditional automation approach, demonstrating the possibility to open new further opportunities for collaborative robots when small/medium batch sizes are involved.

Introduction
The increasing diversification of customer needs as well as greater regulatory pressure [1] add further costs and complexity to industrial operations. Companies throughout the world have embraced mass customization in an attempt to avoid these pitfalls and provide unique value to their customer in an efficient manner. Readily available information technology and flexible work processes permit the customization of goods or services for individual customers in high volumes and at a relatively low cost, but mass customization can still produce unnecessary cost and complexity. Customers can no longer be thought of as members of a homogeneous market grouping. In fact, the concept of markets also needs to be redefined as customization becomes more commonplace.
Instead of focusing on homogeneous markets and average offerings, mass customizers have identified the dimensions along which their customers differ in their needs. These points of common uniqueness reveal where every customer is not the same. In addition, it is at these points that traditional offerings, designed for average requirements, create gaps in customer satisfaction: the difference between a company offering and what each customer truly desires [2].
Due to this, automation is currently undergoing a strong process of evolution, keeping the pace with an economic context characterized by dynamic manufacturing systems: demand becomes more and more unstable, with batches of production shrunk and highly customized, requiring companies to be incredibly flexible in changing from one production to another quickly and cheaply. In such production systems, as well as in artisan enterprises, robotics penetration is rather low due to the limiting characteristics of traditional automation: rigid, fixed to a single process and demanding steady and high volumes, to repay the large investment costs and risks.
To meet these needs, scientists around the world are trying to implement modern solutions to traditional robot controllers aimed at defining control procedures to allow a safe interaction between human and robot [3] and advanced programming methods based on the physical interaction between human and robot (e.g., learning by demonstration [4], gesture and voice communication [5,6]).
Some experimental user interfaces are also being proposed for traditional industrial robots, since, due to the specificity of operations they can carry out, the need of adapting their control programs to the changing assortment is an important issue [7][8][9]. However, collaborative robots have certainly a great potential to satisfy the needs of this variable customer demand [10,11]. They are often used as traditional automation, i.e., fixed to a single process with the only advantage of not requiring safety cages and therefore lowering investment costs [12]. On the other hand, they could be exploited on assembly lines: dynamically adaptive to new production requirements and easily reconfigured and reprogrammed to the changes in production line [13]. The idea previously investigated by researchers, and further explored in this paper, is to transform these robots into tools that can be applied by non-expert robotics users into the desired production process when they are actually needed, according to the daily production agenda, in a fast and easy way.
Four main challenges arise when trying to implement a methodology to exploit cobots in the above-mentioned conditions; these are the starting points of this project: • Expert engineers are needed for designing, programming and testing the robotic application. • Programmers need to know the workstation requirements for developing the precise production process.

•
The robot adoption in such production process conditions has to be technically justified, since small and varied batches are involved. • Investment costs are certainly significant, and the economic return has to be assured.
Robot programming is recently evolving from the traditional written language to new more accessible directions. For example, kinesthetic teaching applied to a walk by demonstration approach simplifies a lot the workload required for programming a machine, and its path towards industry is on track, being regulated by ISO/TS 15066.
An interesting approach in the field of easy-programming research is the task-level layered framework, as described in [14]. A productive process, referred to as a task, is constituted by a sequence of standard, modular and parametric blocks named skills [15], arranged as a state machine architecture [16]. Skills may have different structures, implying a motion and a trajectory component as in [13], or have a slightly modified template as in [17][18][19][20][21]. In general, a skill is composed of a pre and post check phase, where preconditions and objectives are evaluated, and an execution phase in which elementary activities or component manipulation are performed. It must be remarked that most state-of-the-art task level programming still requires engineers or experts for creating a real industrial application, thus reducing the operative range of non-expert users. Some recent work is aimed at developing a framework that alleviates the problem of a high programming effort, e.g., exploiting the advantages of Learning by Demonstration, Learning by Programming and Learning by Interaction, combined [22].
Another relevant issue is the impossibility for programmers to standardize, in advance, the workstation, which would be needed for a reliable utilization of robots in the production process. Indeed, centering and positioning must be considered to guarantee the typical precision recognized in robotic applications. In [23] the robot can find the workstation center by means of its vision system, recognizing a QR code and using it for the correct positioning of the machine's Cartesian origin. Other calibration methods have been investigated by researchers, for example in [24] by applying hand-eye calibration or laser triangulation aided by image processing.
The last issues to be considered are related to the economic feasibility of the robotization process. Investing in robotics and automation requires great capital, usually repayable only if high and constant volumes are involved. The economic investment return can be guaranteed only by transforming robotics, typically rigidly utilized as a stable workstation, into a flexible tool that can be applied to different processes without involving significant costs or times.
The methodology proposed in this paper, named Interactive Refinement Programming (IRP), allows non-expert users to newly develop a production process by refining, step by step, built-in standard and parametric tasks in an easy way. The elements of novelty in this approach is a first translation phase carried out by engineers of production processes (in which the process to be carried out is translated into a robotic metalanguage based on skills), followed by an on-line setup and correction carried out by the non-expert user. Moreover, an economic analysis to generate a standardized way of assessing the convenience of the robotic investment is proposed. This also allows the production department to decide lot by lot the convenience of carrying out the production in a robotic or manual way.
First, a company department skilled in robotics, e.g., engineering of production processes, is responsible for a first translation of the production process from the manual activities, typically assigned to the operators, to a list of skills, thus creating a robotic metalanguage. This code structure is built by adopting pre-built skill blocks (which is a topic widely studied in the literature [17,18]) developed in our case by using the ABB code robot studio. At this stage the code is still not executable by a robot, since the created list of skills still needs an initialization and to be characterized by the actual process data. The process is then refined and finalized by a non-expert user into the real production process, by inserting the required parameters and correcting possible errors that may arise during its execution. From the point of view of industrial operation, this approach allows the shift of some operations typical of the production line department to the design stage. Each product can be conceived directly with its assembling procedure, and the robotic code structure can be directly given as an output of the design stage.
In production lines, non-skilled operators in the use of robots are enabled to provide input data to the pre-built code. The robot itself already has an inbuilt behavior that allows skill initialization. Moreover, the machine is able to drive a correction phase: even if each skill is standardly programmed, and the robot thus knows how the required activities or manipulations must be carried out, the specificities of each different workstation may cause some errors that make the task not properly executable. Built-in correction strategies are then preliminarily implemented, so that the machine can guide a non-expert user in this correction.
The paper is organized as follows: Section 2 gives an overview of the proposed methodology, of the exploited hardware and of the developed software. Section 3 details the Interactive Refinement Programming procedure. In Section 4 an economic analysis to evaluate a standardized way of assessing the robotic investment is proposed. The industrial test case and results are described in Section 5 and, finally, conclusions are drawn in Section 6.

Overview of the Proposed Methodology
The intrinsic properties of interaction and security of collaborative robots permit the flexibility needed in the reference context for this work, i.e., the possibility of being relocated and reused in an easy way. A widespread solution of cobots available on the market is the single-arm configuration with 6 or more Degrees of Freedom (DoF) and a payload on the order of 5-10 kg. An exception is made by the ABB YuMi, a double-arm, 7 + 7 DoF robot with a payload of 0.5 kg per arm. All the mentioned cobots present useful features that are exploitable to achieve the target of flexible implementation, such as the hand-guiding modality and the multi-modal interaction system (composed of a vision system, voice recognition and force/torque sensing), which are both very useful to interact with humans.
To obtain the required high level of flexibility, the workstation and all the related equipment (grippers, pliers or input and output systems) must be as general and standard as possible. A suitable solution consists in developing a general frame and some specific dowels per product, allowing for variation in as few components as possible when changing the production process. Obviously, the possibility of developing some specific components as well is still valid, but it would increase the implementation and setup times.
To increase system mobility, it could be useful to mount the robot on a cart, which can be manual or automatic, and to organize the shop floor into different fixed workstations which can be used both by human operators and robots independently. Each station should be of course provided with a proper blockage body and with a calibration system useful to correctly setting up the workstation itself. (This last part of activity is not carried out in the present work.) As for the software, in order to obtain a tool that can be completely handled by a common robot-non-expert worker, the solution adopted is a pyramidal parametrized programming approach: a layered pyramidal framework composed of Primitives, Skills and Tasks, depicted in Figure 1:

•
Primitives are the basic robot code command lines. • Skills are blocks of code, composed by Primitives, that allow the robot to execute a specific operation.

•
Tasks are logical and precise sequence of Skills used to allow the robot to complete an entire production process. Each block of code, named Skill, represents a real activity or operation performed by the robot on the product to be manufactured. It is composed of a series of basilar command lines, called Primitives. The choice of creating a Skill equivalent to a production step is driven by robotics experts, in charge of developing Primitives and Skill libraries according to what the operator is used to doing during manual operations.
The structure of the considered Skills is divided into three main parts, reported in Figure 2.  Pre-Check: the preliminary verification that has to be done before starting the execution of operations; the effective Execution can start only if all the Input States of the system have been verified. • Core Execution: the parts that effectively execute the working cycle; the Core is always preceded by an initial movement to the working position, before starting the actual operation on the workpiece. In parallel to the Execution, a Continuous evaluation of the process in the workstation is carried out, and, consequently, certain methods to handle occurring errors are implemented.

•
Post Check is performed when the working cycle is completed, in order to verify if the Core has correctly been executed and if the Output States are equal to the expected ones.
When a sequence of skills is created, each block, therefore, has Input and Output States which represents all the variables necessary for the execution of the current working cycle and for the execution of the following one.
Tasks, at the top of the layered pyramidal framework of Figure 1, are composed by connecting different Skills in sequence. The sequence can also present different branches, in a sort of state machine in which each block is executed when the value of the input state is correct. Different branches of the sequence can be thus executed on the basis of what has happened before.
The chosen Skill architecture is then very useful in order to keep what is happening under control and to avoid inconsistencies or mismatching errors. Input and Output States of each Skill, and thus Pre and Post Checks, are fundamental for the correct and congruent creation of a complete robot running code.
In the above-described scenario, the competencies required for creating a robotic application are split among different players. Robotics experts write the code for primitives and skill libraries, which are created after an analysis of all the involved production processes in the company, to make them as standardized as possible. The job of creating the application-generating a list of skills and thus creating a robotic metalanguage-is then assigned to the production process engineering department, who already possess the required competencies. Finally, shop floor non-expert users merely have to set input parameters for each skill during a Teaching Phase (which specifically relates each skill to the particular process), and to carry out, as a second step, a Correction phase to fix occurring errors. Non-expert users are helped in this phase by a software managing the entire teaching and correction procedure through a Graphical User Interface. These two phases will be described in detail in the following section.
Skill based programming has been extensively studied in the literature [17,18]. In this work, it has been adopted as an instrument to define and test an overall procedure accounting for every step in the flow of operations in an industrial environment, ultimately enabling the fine-tuning of a robotic cell by non-skilled operators.

Interactive Refinement Programming Procedure
This section describes the Interactive Refinement Programming (IRP) procedure, through which non-expert users can carry out the teaching and correction phases, ultimately leading to task execution. The main steps of the IRP are represented in Figure 3.

Setup
Engineers in charge of designing and developing new products and manufacturing processes have to define the skill tree being executed based on operations traditionally done by hand, generating a list of skills in a robotic metalanguage. This sequence, at this stage, contains general purpose items that can still take shape accordingly to the context of the considered process. The task is not yet ready to be executed by the robot, since the inputs of each skill are still to be defined. This phase, named the Translation Phase, also includes the design and development of specific hardware or software components, in case specific adjustment of hardware or software, different from the general bundle, is required.
After the Translation Phase is completed, the operator in the production department receives the list with the sequence of Skills and the instructions to manage production (i.e., instructions and information for the operators on how to handle the workstation). The workstation can be set up and all the equipment mounted and verified according to the prescriptions in the list. When the station is ready, the setup phase is over. The operator uploads the sequence of Skills into a manager software in charge of driving the beginning of the Teaching phase for each Skill.

Teaching
If the manager software detects it is the first time a specific production process is implemented on a robot, a procedure to insert the precise input parameters for each skill is run. During this teaching phase, the user, guided by the manager software, exploits the interaction capabilities of the cobot to set the correct parameters needed for the execution of each skill. This procedure can be done in different ways, for example by using the keyboard and moving the robot into the correct positions using the teaching pendant (as in the present work), or by exploiting kinesthetic teaching (and thus moving manually the robot in the necessary positions) or, finally, by exploiting gestures [5] and voice recognition systems [6,25] or even more advanced interaction methods [26].

Correction
Once all the input parameters have been assigned, the robot contains an effectively runnable program. However, the execution could still find errors that should be detected in advance and corrected. Thus, a Test and Correction phase is performed: each operation is executed slower than the actual executing speed, so that the operator can supervise and intervene if any error or problem occurs. In such a circumstance, the program stops and the issue can be recovered through proper editing. Some typical problems are related to the arm movements (e.g., singularity points, wrong configurations, out of reach points or physical interference with other objects in the working area) or to the gripping/contact forces.
Some predefined corrective packages have been developed and preinstalled into the manager software to drive error recovering: this is the fastest and most straightforward procedure, which, however, requires all the possible occurring errors to be known in advance to permit the development of a pertinent correction procedure for each one. The list of correction packages developed is the following: • Automatic Trajectory Generator. • Waypoints Addition: the movement of the robot can be stopped and some passing points can be added to the path. • Avoid Singularity. • Lead by Demonstration: the operator drags the robot along the desired path between two points and the robot records the trajectory in order to re-execute it. • Force routine: the robot closes the gripper repeatedly around an object, at each iteration increasing the force until the operator confirms that the object has been grabbed correctly.
When the Correction phase has been completed for each Skill, a low-speed test is performed in order to verify the correctness of the overall task.

Execution
At this point, the Task is ready for the Execution. The complete IRP procedure is obviously necessary only the first time that the process is implemented: the parameters are then saved and made available for the next time the same product will have to be manufactured. Nevertheless, each time a task has to be redeployed, the station must be recalibrated, and thus it is appropriate to initially perform a Test Execution and, eventually, again the Teaching and Correction steps. When everything is correct, the production cycle can finally start.
In manufacturing factories whose production is highly variable and whose products are customizable, it may occur that a production process for a customized product is slightly different from the process of the basic product. Thus, this solution allows for slight modification of an existing Task and for saving this as new one by adding some other skill branches to the state machine tree. This would maintain the desired grade of flexibility required by these kinds of production systems.

Economic Analysis
Investing in robotics requires high costs that should be paid back by the possibility of reducing labor hours, saving annual workforce costs or increasing production capacity.
In order to assess the economic convenience of installing a robotic cell, a deeper focus on the production activities of the department is needed. Every process should be analyzed to First evaluate its "robotic feasibility" (i.e., complexity of the operations to be carried out by the robot) and then its economic impact. The threshold value N thr for the lot size that makes the adoption of robots convenient is computed by comparing the total robot setup time T robot setup (from off-state to application finalized) with the time that would be required to the operator if production activities were performed manually. These two times are equaled in Equation (1): T robot setup = N thr × t robot act. + T man setup for robot activities On the left side of the equation, the term T robot setup represents the robot setup time, consisting of the sum of:

•
Robot positioning in the specific workstation (automatically or manually) and anchorage through a mechanical or magnetic braking system.
• Robot controller startup routine. • Setup of the hardware components required for a correct execution of the task and product feeding.

•
Teaching, correction and low speed test phases for every skill composing the Task.
On the right side of Equation (1), t robot act represents the manual cycle time, per unit, of the activities that should be instead allocated to the robot. When multiplied by the number of pieces in the lot (N thr ) this gives the time that an operator would need to manually perform all the batch operations. Finally, T man setup for robot activities is an additional setup time of those activities that should be made by the workforce in standard manual operation, and that instead can be allocated to the robot in the automatic procedure. The lot threshold value N thr obtained by Equation (1) can finally be multiplied by a safety coefficient to adopt the robot in a more conservative way, only when the saved hours are a relevant percentage of the required workforce time.
The annual working hours saved for the specific process j (h saved j ) are then computed as in Equation (2) only taking into account the batches i bigger than the defined threshold value N thr , which can therefore be carried out through a robotic cell. In the Equation, the saved time is evaluated by summing up, for each batch i, the manual cycle time of the activities to be automatized (N batch i,j × t robot act j ) and the setup time that would be necessary to the operator if the activities were performed manually and by finally subtracting the time needed to setup the robot.
Dealing with the overall investment, monetary benefit is computed in the easiest scenario by summing up, process by process, the freed person-hours multiplied by the hourly workforce cost. On the other side, the investment costs are the robot, its moveable station, and all the general and process-specific hardware and software costs for developing the required components or software modifications. Comparing these fixed costs and the annual savings, it is possible to compute the payback time and to assess the convenience for the case of interest.
Since the target companies of the proposed work deal with a truly dynamic market request, in order to introduce variability in the study, a Monte Carlo analysis has been used to simulate the demand planning and the consequent outcome on the production process.
Starting from the historical data for every demanded product of the portfolio, the probability density functions of orders' date/size and yearly frequency have been simulated, and random values have been extracted. The constraint of robot production capacity has also been introduced, and the computation of annual savings has been repeated 150 times to get a distribution of the investment benefits, whose average has been used for computing the payback time.
A specific performance indicator on an N-year basis, named Implementation Efficiency, has been created for benchmarking different processes in light of robotic implementation. This indicator is computed, as in Equation (3), as the ratio between an equivalent net saving (i.e., savings S j minus implementation costs in HW and SW) and the equivalent workforce cost (computed by multiplying the hourly cost by the total man cycle time necessary to manually perform all the activities).
In the equation, N is the year horizon upon which the indicator is computed. The equation thus computes the ratio between the yearly net savings if automation was applied, and the production costs if the operator performed manually all the activities.

Industrial Test Case
The proposed methodology has been tested in an industrial environment, in collaboration with the ABB Building Automation department in Vittuone (Milan, Italy). This factory unit, dealing with the manufacturing of personalized electronic components, is aligned with the project target, since its production is highly unstable and customized and it involves small batches and large variety and variability.
The test case is carried out on the production process regarding firmware updates in motherboards for security sensors. This working procedure is rather simple, but it contains crucial ingredients for assessing the feasibility of the proposed method. The board has to be picked out from an input tray, placed on a cable fixture connected to the PC, updated and then picked out and placed on the output tray. The ABB YuMi two-arm robot was used.
For the test case execution, the following required hardware and software was developed: • Hardware: a multi-board 4 × 4 tray module, ad-hoc fixture and specific pliers (3D printed). • Skills: pick and place are the two most important skills developed, completely standard and parametric, allowing for the performing of activities on a large variety of components in all the possible directions. They are developed in the ABB Robot Studio Software.

•
Program manager: the program manager is a no-motion additional software uploaded on the robot controller to coordinate the entire process based on the sequence of skills generated by the engineering office. It allows the management of every phase (i.e., Teaching, Correction or Execution) for every skill, by transferring instructions to each of the two arms and displaying on a screen all the instructions the operator has to follow to define the input of each skill (as an example in the picking operation the operator has to drive the robot in the desired position and set the pose which is saved by the manager software). The communication interface of the developed program is made available on the teach-pendant screen, so that the operator can directly follow the instructions. • Correction packages: lead by demonstration and waypoints addition are two routines useful for solving motion problems, by respectively recording a trajectory directly from the operator dragging the robot, or by adding waypoints interactively to avoid obstacles or force the path to be followed. Two-hands calibration is instead used for improving the precision of a place operation, autonomously calibrating the actual position of the component hold by the robot gripper by using the position of the free arm gripper as a reference (This procedure has to be activated by the operator when a precise insertion is needed). Force calibration and angle rounding routines are instead designed for easing the operator during the teaching phase and for improving the accuracy of teaching-phase parameters. Figure 4 reports an example of the code through which the program manager code was developed (Figure 4a), and a frame of the developed robotic procedure, in which it is visible that the two arms can operate at the same time (Figure 4b). In the figure the fixture specifically designed to house the electronic boards is visible, for each of the two arms. The robotic process has been created and set up by a non-expert user, revealing the great potential of the methodology. Two series of tests have been carried out: a first one with a non-expert user who, however, is up to date on robotic programming. The second series of tests have been carried out by a person who had never used a robot before. In both cases, the operator's learning was rather fast, since the entire process is intuitive and guided by a basic and practical graphical interface.
The results achieved by the two different users were not systematically different in terms of average values and standard deviations, so that the presented results do not differ for the single operator. This fact demonstrates that having skills in robotic does not help to improve usage skills, and the process can be therefore easily set up by every kind of non-expert user. Table 1 reports in the second column the average teaching and correction times of the two non-expert users after several trials (time of 2nd, 3rd and 4th attempts), together with the maximum and minimum times. In the third column the times of the first trial are reported, which are around 25% higher than the following attempts in which teaching and correction times are stabilized.  Table 2 reports the time needed for the slow speed tests, which are carried out as a test after the teaching and correction phases for the skills of the entire task are completed, and the final cycle time per piece. By summing up the times of Tables 1 and 2 it can be observed that the complete application has been created in less than 10 min. The process ended up not being as optimized in terms of trajectory and cycle time as one created by a specialist in production process engineering, but the flexibility expressed by this approach is by far more relevant than process optimization, considering the peculiar production conditions where robots can be continuously allocated to new processes. The robot could perform the task correctly even without any optimization.
From an economic point of view, a Monte Carlo simulation has been conducted on all the processes which could be feasibly carried out by robots in the considered department, in order to assess if, for the reference factory, a robotic implementation is economically valuable. These processes, in addition to the firmware update which is the considered test case from a technical point of view, are related to the following products: USB Charger (wall charger for USB cable, involving both assemblies and customization activities), Crystal Touch Sensor (CTS electronic boards to be assembled and tested, and frontal motherboard to be tested only), Remote Controller for security sensors (sharing part of the process with other products, as firmware update and laser marking) and product customization. These are only the production processes which involve at least one activity that can be allocated to YuMi, respecting technical feasibility and robot performance. All the processes of interest have been simulated in the Monte Carlo simulation based on probability functions evaluated from historical data and forecast demand. Table 3 reports a synthesis, for each of the mentioned processes, of the main input data (i.e., time allocated to YuMi, YuMi setup time, average lot size, pieces produced in a year) and output data obtained from the Equations (1)-(3) described previously in Section 4 (i.e., Lot Size threshold, Saved person-hours, implementation efficiency). It can be noted that the assembly of the top and bottom parts of the Crystal Touch Sensor (CTS) accounts for the great majority of saved person-hours, given the high quantities produced per year and the large percentage of activities which can be allocated to the robot. Investment costs are about 50,000 € (i.e., robot 40,000 €, mobile station and general hardware 2000 €, general software bundle 3000 €, operator training 3000 €, process implementation costs 2000 €), whereas saved person-hours are quantified to be in total 656 h/y, which, multiplied for an average the operator hourly cost, leads to an annual savings of 19,688 €. The payback time is therefore around 2.5 years, oscillating with ±0.5 years depending on a positive or negative scenario. In addition to the standard case, indeed, two further scenarios have been analyzed, repeating the simulation with an increased or decreased demand and batch size of 10%.
The mentioned payback scenarios are represented in Figure 5. The two additional cases reported in dashed lines make reference to a specificity of the fiscal regime that the factory department is subjected to, which further reduces the payback time of the investment.

Conclusions
The proposed Interactive Refinement Programming (IRP) is an approach aimed at simplifying the creation of a robotic application, allowing non-expert users to actively setup a robot guided by the machine itself, and to correct any occurring error with an iterative procedure. A pyramidal approach is based on primitives and general skills to be developed by expert engineering, which can then be connected in a tree structure to generate a specific task. The only thing that shop floor non-expert users have to do is to provide a set of input parameters for each skill during a Teaching Phase, which specifically relates each skill to the particular process, and a correction phase to fix occurring errors. These teaching and correction phases have been driven by a self-developed program manager software uploaded on the robot controller and able to display instructions on the teach-pendant screen to assist the non-skilled operator.
Ad hoc performance indicators have been created for the economic assessment of process automation benefits and for the daily management of production orders once the robotic application has been set up.
The proposed approach was validated through a real industrial case-in which the base software and hardware needed for the application were developed by expert engineers whereas the actual set-up of the robotic application was established by non-expert users in a very short time-and demonstrated the flexibility of the proposed method. The complexity in creating a robotic application has been drastically reduced in light of easy programming efforts. Collaborative features of cobots are exploited at a higher level, not only during execution but also for correcting and finalizing the application itself.
The main limitation regards the fact that the proposed method is intrinsically based on a trade-off between task optimization and flexibility: skills are designed as generally as possible to obtain the needed flexibility, which implies that the resulting tasks cannot be optimized for the specific process in terms of trajectories and cycle time.
The presented results are a further step toward the implementation of robotics in craft manufacturing, overcoming the limitations of traditional automation and current use of collaborative robots.