Making a high-mix make-to-order production system lean

Abstract

A high-mix, make-to-order production system can become inefficient when non-value added operations consume too much time, space or labour. To address these issues, cell re-layout is conducted and a CONWIP system is proposed. The cell re-layout started with data collection on current layout, product mix and routings, then the current layout was modified to develop several alternatives, and finally the best alternative was selected based on a set of criteria. The Pull system design began with comparison between Kanban and CONWIP with respect to an actual production system, and then the CONWIP system was selected and a sample case study based on ARENA 12.0 was included to study the characteristics of CONWIP. Finally, transformation of the actual production system to CONWIP was studied in ARENA simulation to determine its optimal CONWIP setting. It can be concluded that the cell layout resulted in improved operator efficiency and savings in area occupied, while the CONWIP system leads to reduction in amount of work-in-process, and stabilization of manufacturing lead time.