To realize the single piece production process and maintain the fluidity of the production process, the following two points must also be achieved:
Synchronization ------ In the uninterrupted continuous production process, each process in the production unit must be balanced, and it is required to complete each operation in roughly the same time.
Balance ------ Reasonably arrange the work plan and staff to avoid that the working load of a process is sometimes too high and sometimes too low. However, in some cases, a certain amount of WIP inventory must be retained, which depends on the handover time of two adjacent operations.