The following problem is a real problem from industry that demonstrates the challenges in understanding the capacity of a process. While taken from manufacturing (not services), this problem is typical of many systems. It has the following features that we often see:
1. The process is composed of several resources.
2. Resources are shared across assembly lines (i.e., individuals must multitask.) 3. The resource that limits hourly production is not the same resource that limits the process lead-time!
The problem: Since 2002, Honda’s 1800cc cruiser style motorcycle, the
VTX1800, has been assembled in its Marysville, Ohio plant from four major subassemblies. All resources are indicated in bold.
• The first subassembly produces the engine from three activities: a left and right part of the engine block come out of the automatic mold every 2 minutes. These two parts are welded together, requiring 1 minute of the continuous welding machine. Finally, it takes the engine assembler 3 minutes to insert the two pistons and valves.
• The second subassembly produces the frame in two steps: first heavy metal bars are bent in the 10,000 lb press in 1 minute. Then it takes 3 minutes to setup and weld the multiple bars together with the same continuous welding machine to produce the frame.
• The third subassembly consists of the front and rear fenders, both of which are formed using the same 10,000 lb press for 1 minute per fender.
• The forth subassembly makes the seat. It takes a seat assembler 7 minutes to cut the padding, put it on a preformed piece of plastic, and wrap the two with synthetic leather.
• The first the four subassemblies are put together in final assembly.
Adding the handlebar, front and tail lights, radiator, wheels, drive shaft, brakes, cables, fluids and electrical wiring produces a new bike that is ready for test drive. Final assembly takes one person 30 minutes for one