The CONWIP production control system: Review and research issues

Abstract

Since its introduction more than a decade ago, the CONstant Work In Process (CONWIP) production control system has received a great deal of attention from practitioners and researchers. In this paper, different contributions are reviewed according to three issues: operation, application, and comparison of Conwip. Referring to the operation of Conwip, some implementation decisions, such as lot sizing, have been overlooked, most studies being focused on card setting and job sequencing. Besides, no research has been conducted to show the relative importance of the different implementation decisions on the system performance. With respect to the application of Conwip, although it has been successfully implemented in many manufacturing environments, there are no studies to assess the impact of the manufacturing conditions on the performance of the system. Finally, most of the comparisons of Conwip with other production control systems suffer the lack of a unified framework for comparison where each system is tested under optimal parameter setting. The latter may explain partly the contradictory results found in the literature. It is believed that all these issues are relevant subjects for future research.