Cyclic Scheduling of Lots with Setup Times

The paper reports very recent results dealing with a prevalent case of so called cyclical manufacturing/production systems supplying various products in lots with inter-lots setup times. Setups appear between series of different goods. We propose a convenient approach for modeling and approximate solving, which uses our previous findings developed already for classical systems occurring in operations research (OR) field, namely job-shop scheduling problem with setups, as well as those proved for cyclical job-shop. Analysis is carried out for a general structure of manufacturing system, namely the job-shop scheduling problem because of practical applicability of this model. We consider chiefly the modelling aspect by using combinatorial representation of a solution with the support of unique class of graphs. We propose the method of finding/evaluating the minimal cycle time for given processing order by using the graph and some special features of the problem.