Chandrasekharan Rajendran

Bio: Chandrasekharan Rajendran is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Job shop scheduling & Flow shop scheduling. The author has an hindex of 52, co-authored 192 publications receiving 9404 citations. Previous affiliations of Chandrasekharan Rajendran include Indian Institutes of Technology & VIT University.

Metaheuristics for solving economic lot scheduling problems (ELSP) using time-varying lot-sizes approach

Abstract: The Economic Lot Scheduling Problem (ELSP) on a single facility (or machine) with the time-varying lot-sizes approach and with sequence-independent/sequence-dependent setup times of parts or products is studied in this paper. The objective is to minimise the long-run average inventory carrying cost and setup costs of products. While the frequency of production of a product is determined from an existing heuristic, we allow for possible changes in the heuristically computed frequencies of parts (or products) and hence attempt to reduce the total cost per cycle during the metaheuristic search process. Three metaheuristics, namely, a Genetic Algorithm (GA), a Simulated-annealing Algorithm (SA) and an Ant-Colony Algorithm (ACA) are proposed. A new crossover operator is designed and incorporated in the proposed GA. New perturbation schemes are incorporated in the proposed SA. In the proposed ACA, the initialisation and updating of pheromone intensity (or trails) are done subject to certain conditions presented in this work. The best-performing existing heuristic algorithm and the proposed algorithms for ELSP with sequence-independent setup times of products are evaluated by considering a couple of benchmark problems and by generating many problems with different number of products and comparing the solutions. In addition, we consider the case of sequence-dependent setup times and the associated setup costs. The performances of the existing algorithm and the proposed algorithms are evaluated by considering a proposed (computationally simple) lower bound on total cost per cycle with the consideration of sequence-dependent setup times and the associated setup costs of products. The computational performance analyses reveal the effectiveness of the proposed metaheuristics. [Received 2 September 2006; Revised 5 January 2007; Accepted 30 January 2007]

Distribution and Equitable Sharing of Value From Information Sharing Within Serial Supply Chains

Abstract: This paper studies the incentive issues that arise when firms in a multilevel supply chain create value jointly by investing in information sharing. We consider three types of information sharing: (1) supply-chain-wide information sharing; (2) downstream information sharing; and (3) upstream information sharing. We showed that the value of information sharing is higher for the upstream firms than for downstream firms regardless of information sharing type. Furthermore, the value of information sharing for any firm is higher under downstream information sharing than upstream information sharing, and the incremental value of information sharing to a firm decreases when more downstream firms share information. Therefore, if there is a cost associated with information sharing, then upstream firms have an incentive to free ride on downstream firms' information sharing efforts. These results suggest that serious incentive misalignments may impede supply-chain-wide information sharing, even though it maximizes the value to the supply chain, and that a mechanism to distribute the overall surplus equitably may become essential. If a contract distributes the surplus according to each firm's incremental contribution to it, then firms that are in the middle levels of the supply chain receive a higher share than those that are in either end of the supply chain. That is, interestingly, neither the firm that possesses the information that is propagated throughout the supply chain by information sharing nor the most upstream firm realizes the highest value from information sharing obtains the maximum share of the surplus generated under such a contract.

Dispatching rules for scheduling in assembly jobshops - Part 2

Abstract: In this part of the paper, we present the development and evaluation of dispatching rules for scheduling in jobshops manufacturing multi-level assembly jobs with the performance measures reated to tardiness. We present a new definition of 'operation due date' in the context of assembly jobs and use it in the development of dispatching rules. A simulation study is carried out to evaluate the performances of the existing and the proposed dispatching rules with respect to different measures of tardiness. We also measure their performances with respect to different measures of flowtime and staging delays. The results of the study indicate that the proposed rules perform better than the existing rules.

The Design and Analysis of Experiments

Abstract: THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON

Out of the Crisis

Abstract: According to W. Edwards Deming, American companies require nothing less than a transformation of management style and of governmental relations with industry. In Out of the Crisis, originally published in 1982, Deming offers a theory of management based on his famous 14 Points for Management. Management's failure to plan for the future, he claims, brings about loss of market, which brings about loss of jobs. Management must be judged not only by the quarterly dividend, but by innovative plans to stay in business, protect investment, ensure future dividends, and provide more jobs through improved product and service. In simple, direct language, he explains the principles of management transformation and how to apply them.

Evolutionary algorithms for solving multi-objective problems

Abstract: List of Figures. List of Tables. Preface. Foreword. 1. Basic Concepts. 2. Evolutionary Algorithm MOP Approaches. 3. MOEA Test Suites. 4. MOEA Testing and Analysis. 5. MOEA Theory and Issues. 3. MOEA Theoretical Issues. 6. Applications. 7. MOEA Parallelization. 8. Multi-Criteria Decision Making. 9. Special Topics. 10. Epilog. Appendix A: MOEA Classification and Technique Analysis. Appendix B: MOPs in the Literature. Appendix C: Ptrue & PFtrue for Selected Numeric MOPs. Appendix D: Ptrue & PFtrue for Side-Constrained MOPs. Appendix E: MOEA Software Availability. Appendix F: MOEA-Related Information. Index. References.