JIT and the Effects of Varying Process and Set‐Up Times

There is considerable interest in the Just‐in‐Time production method and the potential benefits that can be realised, particularly in a reduction in the work‐in‐progress inventory. The article reviews some of the salient prerequisites necessary for successful implementation of the JIT system. Two major factors are examined using a simulation model. Results indicated that contrary to widespread conjecture it is not necessary to maintain a balance in the process times between work stations. With the choice of a suitable scheduling rule, such as SPT/LATE, the system performance can be superior to that for constant process times. It is also found that the pull system is relatively unresponsive to a heavy imposed loading and process utilisation is generally low. Finally, smaller batches give better system effectiveness but the improvement is less significant than for the conventional push system.