Optimal production planning for workshops with workpiece transferring delay between flexible manufacturing systems

The paper addresses the problem of the optimal production planning in flexible automated workshops (FAWs) with workpiece transfer delay between flexible manufacturing systems (FMSs). A delay-interaction-based nonlinear programming model of production planning in a workshop is built up and then transformed into a linear programming model by adding constraints. Because the scale of the model for a general workshop is too large to be solved in simplex method on a microcomputer within an acceptable time, Karmarkar's algorithm and an interaction/prediction algorithm are used to solve the model, on the basis of which the corresponding programs have been written. Through production planning examples, Karmarkar's algorithm, the interaction/prediction algorithm and linear programming in Matlab are compared. Thus we show that the proposed approaches are very suitable for optimally decomposing medium-term plans (assigned to an FAW by ERP/MRP II) into short-term plans (to be executed by FMSs in the FAW), especially for the case that workpieces are transferred between FMSs through a shop storage with a delay of a period.