Abstract:
In order to assemble a set of automotive wiring harness it must be used 300 -400 wires varied in color to assemble with many types of connector by manual assembling. While the production demand increases, it causes human errors such as misassembling wires into the connector. A misassemble defect is use quite a long time to repair and impacts to production cost. This research had applied a concept of Fitts’ Law to identify the work performance called Fitts’ Performance. It can be applied to the production planning. The experiment classified working type into 99 patterns (33 wire color x 3 type of connectors) and conducted with the 20 subjects (0 to 5 year experience). The working objective had been defined as operating the task as fast as possible without errors. Fitt’s performance was used to calculate new conveyor speeds. There were 4 conveyor speeds (0.66, 0.75, 0.9 and 1.0 m./min.) that were implemented in the real production line. An analysis results of conveyor speed showed that if the speed was lower than 0.85 m./min., the defect would be decreased but the production rate would be also low and unaccepted. Moreover, the conveyor speed at 0.94 m./min. would provide the lowest rates of total loss (comparing between misassemble correction and production stop). However this conveyor speed did not suitable for 2 year experienced operators because it was based on 4-5 years experienced operators. Therefore the conveyor speed should be set between 0.85-0.90 m./min. based on the experience of the major operators.