The Work in Process (WIP) Control Model and Its Application Simulation in Small-batch and Multi-varieties Production Mode

This paper aimed at the phenomena of the volume of work in process (WIP) great and uneven distribution, which is caused by small batches, various breeds, the complex scheduling, and long production cycle and so on in machine manufacturing industry. The machine manufacturing industry production workshop is taken as the research object in this paper. A work in process (WIP) control model based on the limited capacity is put forward by analyzing the characteristics of multi-varieties of small-batch production, the factors of the state of workshop equipment, equipment parameters (breakdown rate and maintenance rate), delivery deadline, product process similarity and so on. Taking a gear production line of a state-owned large-scale speed reducer’s factory as an example, Witness2003 is used to simulate and optimize the work in process control model of the gear production line. The case study proves that in the manufacturing of small-batch and multi-varieties production mode, WIP volume control problems can be effectively solved by the WIP control model. And the WIP control model provides an effective, workable solution for small-batch and multi-varieties production under the control of the production mode.