“…By looking up the process documentation and onsite verification, we knew that the idler assembled into the gearbox housing when into the assembly line would go through three stations, and the relationship between them is connected in series as shown in Fig.1. For the plant, in order to balance assembly work of the assembly line, two test-beds were arranged at the detection station, that is to configure two staff who can detect parts synchronously, and the two detectors in parallel; two transport upper lines at Transport station, that is to configure two transport staff who can transport parts synchronously, and two transport lines in parallel; and three bench configured at assembly station, that is to configure three assembly staff, and the relationship between the three benches is in parallel [4]. Parts firstly pass by testing stations.…”