Lowest Ratio Mixed Assembly Planning
For that mixture what is the lowest ratio mixed model assembly sequence?
In September 1981, a Japanese management team replaces the American plant manager at the Kawasaki motorcycle plant in Lincoln, Nebraska. One goal of the new managers was to convert the main motorcycle assembly line to mixed model production. The line had been running production lots of at least 200 of each model between line changeovers.
The conversion was expected to take about three months. It required two kinds of exacting preparation:
1. Identification: All parts, tools, cartons, racks, and so forth, had to he clearly labeled so that an assembler would be able instantaneously to identify and select the right one. With a different motorcycle model next on the conveyor, delay in identifying it and all of the parts and tools to go with it would be intolerable. A color-coding system was devised so that, for example, all items related to a KZ6SO motorcycle would he labeled with a gummed red dot. Even the position of the colored dot on the carton, part, or tool had to be precisely designed.
2. Placement. Engineers, material controllers, foremen, and assemblers all pitched in to devise exact locations for all parts and tools at work stations along the assembly line. The assembler, on seeing what the next model of motorcycle is, should be able to reach for the correct parts and tools blindfolded. Better racks, containers, and holding fixtures were designed to feed parts and hold tools in the right positions.
The preparations (which today we would refer to as preautomation) were successful. On January 1, 1983, the main assembly line fully converted to mixed-model production.
At that time, the production volume was at about 200 motorcycles per day. That 200 might consist of the following models: 101) KZ44Os, 60 KZ65Os, and 40 KZ1000s.