When Will You Need This?

When you need to quickly produce intermittent assembly models, vary what is attached during assembly based on the production order. To assemble several types of products on the same line, each requiring different sub components, or vary the assembly time based on that which is being assembled, or to transfer cost and VA time from a sub assembly to the main component.


Variable Assembly model image

Model Object

The following model object will be used to produce intermittent assembly model: Assembly \ Variable Assembly.

Variable Assembly model object pasted


Base Entity: The entity to which other items will be assembled. For example in truck assembly line, the base entity would be the frame.

Subassembly: The entity assembled to the Base entity (engine, transmission, front and rear differential, etc.)

How It Functions

When the base entity reaches an assembly station, an attribute defines the quantity to be attached. This attribute is also found in the attach quantity of the attach route from the subassembly

how it functions Variable Assembly

If the attribute (a_MO_Qty1 ) of the base entity is set to 4, then 4 subassemblies will be attached and time to assemble (also defined by an attribute) 4 will be added. If the attribute of the base entity is set to 0, then no request will be made to assemble, and zero time will be added for assembly.

In addition, 2 variables (see the description of variables below) transfer the VATime and Cost from the subassembly to the main part.

How to Use the Model Object

1. Open Your Model

Open your model or create a new blank model.

2. Insert the Model Object into Your Model

Locate the appropriate location in your model where you would like to place the model object, move the view to the location and then insert the model object.

3. Connect to Your Model

1. Insert the model object for each subassembly.

Variable Assembly model object pasted

2. Build the assembly process tying into the newly placed assembly stations.

building the assemble process in Variable Assembly

3a. Build each subassembly process and connect to the inventory queue.

build subassembly process in Variable Assembly

3b. If multiple subassemblies need to be connected, do the following:

1. Place a new assembly station for each sub assembly.

place new assembly in variable assembly

2. Move route head from the extra assembly stations to the assembly station you will be using.

move route from subassembly to assembly in Variable Assembly

3a. Copy the action logic from the unused assembly stations

copy action logic from unused assembly in Variable Assembly

3b. Add it to the assembly station you will be using.

add action logic to assembly station Variable Assembly

4. Delete the extra assembly station, in our case Assembly 2.

4. Add scheduled arrivals with attributes set to define assemblies to be performed. Arrivals can be “read in” in seconds from an Excel file. The process can be simplified by using the Import Scheduled Arrivals model object.

Import Variable Assembly Arrivals Model Object

attributes via scheduled arrivals in Variable Assembly

4. Completion

The Variable Assembly model is now integrated into your model, you should now be able to save and then simulate the model.

Attributes, Variables, Scenario Parameters and Scenarios usage


1. a_MO_Qty1 to X: Defines the quantity of part1 to be assembled at assembly station 1. If the quantity is set to zero then no assembly will occur.

2. a_MO_Assy_Time1 to X: Defines the assembly time for 1 part to be assemble at assembly station 1 (in hours — this can be changed quickly to minutes or seconds by going to the action logic of the assembly station.


1. v_MO_TXR_Cost1 to X: Used to transfer cost from the subassembly to the receiving part.

2. v_MO_TXR_VA1 to X: Used to transfer the Value Adding time from the subassembly to the receiving part