The assembly operations within the BMW factory near Spartanburg, SC, have under-gone a transformation to help make the operation more effective. The plant, where the BMW X5 sport activity vehicle and the Z4 Roadster, Coupe and M are produced with an annual total volume of approxi-mately 150,000 units, had had two assembly lines. This has been converted into a one-line system. Dieter Lauterwasser, BMW vice president of Assembly, explained, “The one-line system will give us the flexibility to vary model combinations from 100% X5s to 60% Z4s and 40% X5s.” In other words, they’re achieving considerable flexibility while not increasing floor space at the plant. The conversion was conducted with the participation of Siemens Energy & Automation (www.siemenscnc.com; Elk Grove Village, IL), which also worked with BMW on its factories in Dingolfing and Munich. Siemens acted as general contractor for seven projects and subcontractor on three projects within the Spartanburg plant.
A new automation system was devised for the plant. Among the hardware deployed are 20 Simatic S7-400 and seven S7-400F controllers. In addition to which there are some 200 IM 151-F-CPU modules, 2,000 drives, 45,000 I/O devices, 240 switch cabinets, 400,000 meters of com-munications cable, and human-machine interfaces provided by 75 MP 370 operator panels and 121 Simatic OP 77B panels.
Stations were consolidated. Material handling systems replaced and modified. And all of this had to be completed during a three-month period, during which time production ran pretty much unabated.