Simulation-based comparison of push and pull systems in a job-shop environment considering the context of JIT implementation

An investigation of the effects of adopting a pull system in a job-shop environment in contrast to a push system is presented considering the implementation of Just-in-Time production. Implementation of pull systems in job-shop environments should be coordinated with a set of core supporting Just-in-Time concepts, i.e. cellular manufacturing, one-piece production and conveyance, and adaptive material-handling performance. A simulation experiment was carried out to compare the effects of applying these core Just-in-Time concepts on the performances of push and pull systems. The results show that to avoid adverse effects, it is essential that a suitable shop layout and part flow type are adopted for either a push or a pull system based on the extent of set-up time reduction effected by cellular manufacturing. Suitable material-handling equipment can then be employed accordingly to achieve better production performance. In addition, although a push system was always superior to a pull system in the simulated job-shop environment, the performance difference between the two systems was small. This finding implies that pull systems can be expected to bring about greater improvement in production performance than push systems as long as the potential of pull systems in shaping production environments is effectively realized.