Effects of Number of Kanbans in Pull-Production Control Mechanisms-A Simulation Study

The main objective of this paper is to study the effect of number of Kanbans in pull production control mechanisms namely, Constant work in process (CONWIP), Extended Kanban Control System (EKCS) and Hybrid EKCS (HEKCS) when a single line multi-stage manufacturing system; Independent Extended Kanban Control System (IEKCS), Simultaneous Extended Kanban Control System (SEKCS), CONWIP, Hybrid IEKCS-CONWIP (HIEKCS) and Hybrid SEKCS- CONWIP (HSEKCS) when multi line and multi stage manufacturing system. G. Liberopolous and Y. Dallery have proposed the EKCS in 200 0 with two variants of IEKCS and SEKCS. M. L. Spearman has proposed CONWIP in 1990 where as the author is proposing hybridization of EKCS, IEKCS and SEKCS with CONWIP to exploit the combined advantages. Simulation studies were performed to evaluate the performance measures like Production Rate, Average WIP and Average Waiting Time by varying the number of Kanbans 3,5,7 and 10 per stage for all eight-production control mechanisms. Finally, it is concluded that, the performance measures are affected by varying the number of Kanbans for all eight-control mechanisms. When the number of Kanban increases the production rate average WIP and average waiting time also gradually increases for all control mechanisms. Out of eight control mechanisms the proposed mechanisms of HEKCS, HIEKCS and HSEKCS shows better than EKCS, IEKCS, SEKCS and CONWIP. The author further tested with more than ten kanbans per stage, which reveals that same output.