Scheduling algorithm searching only the feasible production sequences for complex batch processes with storage tanks

In chemical batch processes, the feasibility of the production sequence of jobs on successive units depends on the number of storage tanks between the units. When some jobs take different production paths between two batch units, it is more difficult to judge whether the production sequence of jobs is feasible or not. In this paper, for the process which has a complicated flow structure and many storage tanks, the condition that the feasible production sequence must satisfy is derived. Then, using the derived condition, a scheduling algorithm based on the simulated annealing method is improved so that the algorithm searches only the feasible production sequences. The improved algorithm has been applied to a practical large scheduling problem, and it has become clearer that plausible schedules can be generated with a shorter computing time.