Implementation of hybrid Kanban-CONWIP system: a case study

Shop floor control systems are generally major points of discussion in production planning and control literature. The purpose of this paper is to investigate how lean production control principles can be used in a make-to-order (MTO) job shop, where the volume is typically low and there is high variety. This paper examines the procedures involved in implementing a constant work-in-process (CONWIP)/Kanban hybrid system in the shop floor environment and also provides insights and guidelines on the implementation of a hybrid system in a high-variety/low-volume environment.

The authors review literature on Kanban, CONWIP, and CONWIP/Kanban hybrid systems to analyze how lean production control principles can be used in a MTO job shop. The second part focuses on the process of implementation. Using a case study of a manufacturer of electromechanical components for valve monitoring and controls, the paper describes how the operation is transformed by for more efficient shop floor control systems. Real experiments are used to compare pre- and post-improvement performance.

The study shows that the proposed hybrid Kanban-CONWIP system reduced the cycle time and achieved an increase of 38 percent in inventory turnover. The empirical results from this pilot study provide useful managerial insights for a benchmarking analysis of the actions to be taken into consideration by companies that have similar manufacturing systems.

The statistic generalization of the results is impossible due to the use of a single case method of study.

This paper provides insights and guidelines on the implementation of a hybrid system in a high-variety/low-volume environment. The literature on real applications of hybrid CONWIP/Kanban by case study is limited.