Production Planning For Flexible Flow Systems

The book familiarizes the reader with the flexible assembly systems planning and scheduling issues and various operations research modelling and solution approaches. Some of the many topic highlights presented are the overall structure and components of a flexible assembly system, bi-objective integer programming models and algorithms for machine loading, assembly routing, and assembly plan selection, and fast combinatorial heuristics for scheduling flexible assembly lines with limited intermediate buffers. Also the book deals with just-in-time scheduling of flexible assembly lines, and dynamic dispatching algorithms for simultaneous scheduling of assembly stations and automated guided vehicles.

This book presents a unified optimal control approach to a large class of problems arising in the field of production planning and scheduling. It introduces a leading optimal flow control paradigm which results in efficient solutions for planning and scheduling problems. This book also introduces the reader to analytical and numerical methods of the maximum principle, used here as a mathematical instrument in modeling and solving production planning and scheduling problems. The book examines control of production flows rather than sequencing of distinct jobs. Methodologically, this paradigm allows us to progress from initial assumptions about a manufacturing environment, through mathematical models and construction of numerical methods, up to practical applications which prove the relevance of the theory developed here to the real world. Given a manufacturing system, the goal is to control the production, subject to given constraints, in such a way that the demands are tracked as closely as possible. The book considers a wide variety of problems encountered in actual production planning and scheduling. Among the problems are production flow sequencing and timing, capacity expansion and deterioration, subcontracting and overtime. The last chapter is entirely devoted to applications of the theory to scheduling production flows in real-life manufacturing systems. The enclosed disk provides software implementations of the developed methods with easy, convenient user interface. We aimed this book at a student audience - final year undergraduates as weIl as master and Ph. D.

Flexible Manufacturing Systems (FMS) involve substituting machines capable of performing a wide and redefinable variety of tasks for machines dedicated to the performance of specific tasks. FMS can also be programmed to handle new products, thus extending the machines' life cycles. Thus they represent a change from "standardized goods produced by customized machines" to "customized goods produced by standardized machines". This volume contains new and updated material in this field, and will be of great interest to researchers, managers and students concerned with problems related to flexible manufacturing systems.

This book contains a collection of contributions related to the design and control of material flow systems in manufacturing. Material flow systems in manufacturing covers a broad spectrum of topics directly affecting issues related to facilities design, material handling and production planning and control. In selecting the papers to include in this book, the scope was limited to the design and operational control aspects related to the physical move ment of parts, tools, containers and material handling devices. Recent develop ments in this area naturally led to concentration on flow systems involving cellular manufacturing, and automated transport equipment such as automated guided vehicles. However, the concepts discussed have general applicability to a wide range of manufacturing flow problems. The book is organized in five major sections: 1. design integration and justification; 2. cell design and material handling considerations; 3. alternative material flow paths; 4. operational control problems; and 5. tooling requirements and transport equipment.

The book considers the lot-sizing and scheduling problem for flexible flow line production facilities. Flexible flow lines are flow lines with parallel machines on some or all production stages. They can be found in a vast number of industries. A three-phased solution approach is presented that solves the integrated lot-sizing and scheduling problem in a hierarchical manner. The approach is able to handle several important features relevant in industrial practice, such as back-orders and setup carry-over. The developed solution procedures solve practically sized problems in a relatively short amount of time. One of the procedures is based on a novel mixed integer programming (MIP) model, which employs integer variables instead of binary variables. This makes it possible to find (near-)optimal solutions using standard algorithms such as CPLEX. Another procedure uses two nested Genetic Algorithms. An application of the framework in the semiconductor industry is given.

Online scheduling is recognized as the crucial decision-making process of production control at a phase of “being in production" according to the released shop floor schedule. Online scheduling can be also considered as one of key enablers to realize prompt capable-to-promise as well as available-to-promise to customers along with reducing production lead times under recent globalized competitive markets. Online Scheduling in Manufacturing introduces new approaches to online scheduling based on a concept of cumulative delay. The cumulative delay is regarded as consolidated information of uncertainties under a dynamic environment in manufacturing and can be collected constantly without much effort at any points in time during a schedule execution. In this approach, the cumulative delay of the schedule has the important role of a criterion for making a decision whether or not a schedule revision is carried out. The cumulative delay approach to trigger schedule revisions has the following capabilities for the practical decision-making: 1. To reduce frequent schedule revisions which do not necessarily improve a current situation with much expense for its operation; 2. To avoid overreacting to disturbances dependent on strongly an individual shop floor circumstance; and 3. To simplify the monitoring process of a schedule status. Online Scheduling in Manufacturing will be of interest to both practitioners and researchers who work in planning and scheduling in manufacturing. Readers will find the importance of when-to-revise policies during a schedule execution and their influences on scheduling results.