Kevin Bowe and Chip Stehouer at JR automation in Holland Michigan told us about the challenges in designing the large assembly lines that are used in making cars, medical devices and furniture.
The assembly line design starts with the main skeleton, which allows a top-level view that includes the number of stations on the line, where they will be placed and how they will be connected through drives and conveyors. Work can begin on each station, even if an entire station later has to be removed, added or changed. This flexible approach allows the designers to quickly respond to changes from their customers.
Another design challenge in large assemblies arises from distributing the design work across multiple engineers. There is always a challenge making sure that the changes made by one designer don’t impact the work of another designer, or that any changes get communicated to the entire team right away.
JR Automation addresses these collaboration challenges in two ways. First, they assign responsibility for each station on the assembly line to one designer. That way they avoid confusion as to who is working on what. One of the rules is that a designer cannot change the design of model above their station. That means that only the lead designer can make changes to the main skeleton.
With this ground-work set out, each designer on the team can start to design their stations. When a change is made to the requirements, the design leader determines whether it will impact the master skeleton, a station level skeleton, a machine layout skeleton or an even lower level. These changes are then are automatically propagated to every sub-skeleton that is impacted. Robots and other modules are added to the skeletons at fixed coordinate mounting points. When these modules have been added, the designers use simulations to test the actual functionality of the assembly. This functionality consists of proof of contact of parts, robot reach, and cycle time.