Simulating Just‐in‐Time Systems

This paper describes the development and early use of a test bed for Just‐In‐Time GIT) control of Flexible Assembly Systems (FAS). JIT has, up to now, been used in repetitive manufacturing systems. However, increasingly, companies involved in batch production who frequently use Materials Requirements Planning (MRP) approaches, are seeking to achieve the benefits of JIT, and to use Kanban type control at the operational level. The test bed simulation can be configured by the user to model a range of assembly systems each of which can, within limits, be configured by the experimenter. It is built using the SLAM II simulation package. Kanban cards are modelled as resources, as are the individual assembly stations and the transportation devices which carry work between the assembly stations. The test bed can be used to experiment with batch sizes, set‐up times, assembly station breakdowns, various Kanban sequences, varying purchasing lead times, etc. It allows experimentation with the application of the Kanban system to manufacturing systems which are not purely repetitive in nature and more closely resemble batch manufacturing systems.