Production planning in flexible transfer lines

In this article the authors describe a class of computer-controlled production systems referred to as flexible transfer lines. These automated flow lines are used to produce a large and changing mix of parts in high volumes. The important characteristics of these systems are identified by analyzing a line used in the production of high-precision cylindrical components. A key objective in managing these systems is to select the parts to be produced in a given production period, and to determine the mix and lot sizes in which they should be produced to maximize capacity utilization and optimize the contribution generated. The authors discuss the specific features of the system that are important in achieving these objectives, and present a mathematical formulation of the production planning problem to illustrate how these can be captured in an analytic model. They distinguish between this problem and two generic classes of problems to which it is related-the flexible manufacturing systems planning and control problems, and conventional mixed model assembly line balancing formulations. An approach for solving the mixed integer nonlinear production planning problem for flexible transfer lines is discussed, and computational performance on a batch of test problems is presented to illustrate specific features of the approach and to demonstrate its potential value in practice.