Scheduling custom printed napkin manufacturing by P-graphs

The practical problem to be computer aided as a motivational case study is custom printed napkin manufacturing. A process network synthesis based solution is presented that, along with time constraints, can handle scheduling problems while providing clear visual modelling by P-graphs. All the degrees of freedom and limitations of manufacturing process were modelled, and a software module has been implemented to automatically generate optimal production plans. Specialties of the motivational example have to be taken into account, e.g., the optimal selection of the orders to produce in the forthcoming shifts, consumer priorities, deadlines, and the available amounts of raw materials. Moreover, the volumes of each individual production orders have to be optimally shared among multiple candidate equipment units while counting the changeover times. The proposed time-constraint process network synthesis approach is capable to handle all these specialties and provide optimal production schedule by automatically generating and solving a single mathematical programming model. (C) 2020 The Authors. Published by Elsevier Ltd.