A HEURISTIC FOR BATCH SCHEDULING WITH UNIFORM AND NON UNIFORM LOT SIZES IN TWO STAGE HYBRID FLOWSHOP

Recent manufacturing strategy is changing the configuration of manufacturing
environment by adding standby or rental facilities in parallel to meet the delivery
schedule. The hybrid flow shop often encounter in such cases. Scope of this work is to
minimize the makespan by optimal group schedule. This problem is motivated by
demand of an automobile spare manufacturing environment. The customized
mathematical model furnished for m = 2, M(1) = 2, M(2) = 1, k = 6 batch scheduling
problem. The two stage hybrid flow shop is usually NP hard in nature so a heuristic
based approach preferred. The developed heuristic is applicable for both lot
streaming as well as group scheduling. Ten lot streaming cases considered and 296
schedules generated and tested for validation. The mathematical model used to
develop the simulation model in Extend v6 to verify and validate the heuristic
solutions. The uniform and variable lot size cases were considered. Even though
obtaining the optimal schedule by using suggested heuristic the uniform lot size is recommended by considering uniform utilization of critical machine and minimizing
its buffer.