Optimal flow control in manufacturing systems. Production planning and scheduling. Incl. 1 disk
In manufacturing industries, production planning and scheduling are concerned with effectively allocating the enterprise's capacity over a designated time horizon. This book deals with production planning and scheduling in plants where production is continuous in nature both in time and product quantity (as in, for example, process industries) under the assumption that demand profiles are deterministic and known as functions of time. These problems can range from simple one-item models to more general analysis of multi-item multi-resource manufacturing systems, and have been treated extensively in the literature by a variety of mathematical and dynamic programming formulations. The focus of this book is on formulating these same problems as optimal control problems and attempt to solve them using the maximum principle. The book begins with an explanation of the necessary optimality conditions for dynamic optimization problems in the form of the maximum principle, and its use in constructing iterative methods for approximating the solution. Then, control theory models for one-item single facility production and capacity planning problems with known demand profile and backlogs allowed are discussed. These models are treated numerically by shooting-based procedures, and the results explained in manufacturing terms of breaking the time horizon into sequences of full production, partial production, and no production regimes on the production side; and extra capacity selling, maximum or partial capacity expansion, and partial subcontracting regimes on the capacity control side. This is followed by an extension of these approaches to problems with multiple facilities and products characterized by very simple structures. The next part of the book deals with machine scheduling problems in flexible manufacturing systems (FMS) under the same assumptions. However, the setup process which together with the production process defines the dynamics of FMS makes these problems much more difficult to solve. Control theoretic models for these problems are discussed, and their use in constructing numerical methods and heuristic procedures. The authors of this book have made a good contribution to the literature with the optimal flow control paradigm. However, when we discussed this with other faculty working in production planning and scheduling, the reaction to using optimal control to solve problems in the area is not favorable. Practitioners also reacted the same way. One positive aspect of the book is the inclusion of cases (Chapter 9) of practical scheduling. However, these are too simple to provide any insight. We tried to load the software from the diskette provided, but gave up after about half-an-hour, so we were not able to see what it demonstrates. The novelty of the book is in marrying a theoretical tool (control theory) to areas where it has not been applied before. Its success depends on convincing enough number of people that this marriage can produce good results.
scientific article; zbMATH DE number 1349364