Majority of parallel machine scheduling studies consider machine as the only resource. However, in most real-life manufacturing environments, jobs may require additional resources, such as automated guided vehicles, machine operators, tools, pallets, dies, and industrial robots, for their handling and processing. This paper presents a review and discussion of studies on the parallel machine scheduling problems with additional resources. Papers are surveyed in five main categories: machine environment, additional resource, objective functions, complexity results and solution methods, and other important issues. The strengths and weaknesses of the literature together with open areas for future studies are also emphasized. Finally, extensions of integer programming models for two main classes of related problems are given and conclusions are drawn based on computational studies. number of jobs set of jobs number of machines set of machines indices of jobs, i, h =1,…, n the set of possible (resource) modes belonging to job i index of resource modes (k ∊ Ki ) index of machines, j =1,…, m the set of jobs already assigned to machine j number of time periods in the scheduling horizon index of time periods, t =1,…, T processing time of job i on machine j processing time of job i (independent of machine j) processing time of job i when processed in mode k ∊ Ki processing time of job i on machine j when processed in mode k ∊ Ki the size of the single additional resource type the earliest time at which job i can start its processing, i.e., release time due date of job i weight of job i, denoting the importance of job i relative to other jobs completion time of job i maximum completion time of all jobs in the system, i.e., makespan tardiness of job i equals to 1 if job i is tardy, 0, otherwise maximum lateness 
Parallel machine scheduling with additional resources: Notation, classification, models and solution methods