C Rajendran

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. © 2007 Inderscience Enterprises Ltd.

The Fixed-Charge Transportation Problem (FCTP) is an extension of the classical transportation problem. It considers a fixed charge (or a fixed cost) and a transportation cost per unit transported associated with each route. The presence of the fixed cost in the objective function makes the problem difficult to solve, thereby requiring the use of heuristic methods. In this paper, simple heuristic algorithms are proposed, and their performances are compared with the existing best method by making use of benchmark problem instances. Copyright © 2009, Inderscience Publishers.

In this paper we deal with the problem of scheduling in a kanban-controlled flowshop with material handling and finite input and output buffer storage between workstations. The objective is to minimise the makespan of containers. A heuristic algorithm, based on the simulated annealing (SA) technique, is developed. We present a new perturbation scheme and test the effectiveness of the proposed simulated annealing algorithm for solving the kanban-controlled flowshop scheduling problems. The proposed SA algorithm is evaluated relative to the existing heuristic. The results of the computational evaluation reveal that the proposed SA algorithm performs better than the existing heuristic.

The polynomial heuristic of Nawaz/Enscore/Ham (NEH) is one of the best heuristics to minimize makespan in static-deterministic permutation flowshop problems. The NEH approach consists of two steps: (1) the generation of an initial order of jobs with respect to an indicator value and (2) the iterative insertion of jobs into a partial sequence according to the initial order of step 1. We generalize this approach to minimization of makespan, idletime and flowtime, construct 177 different initial orders, and evaluate their performance in the NEH-insertion approach. Based on a comprehensive numerical study, we propose heuristics for all three objective functions that outperform significantly the compared literature-based heuristics.

An experimental investigation of the performance of dispatching rules and a heuristic for scheduling in static flowshops with missing operations is undertaken in this study. The measure of performance is the minimization of total flow time of jobs. Permutation schedules are generated by using the heuristic for scheduling. General schedules, which can be permutation or non-permutation schedules, are obtained by using dispatching rules. Four dispatching rules, including a new dispatching rule, are considered. Two types of flowshops are studied: one with no missing operations of jobs and another with missing operations of jobs. In the latter type of flowshops, jobs with varying number of missing operations are considered. An extensive investigation of the performance of the dispatching rules and the heuristic is carried out. It is observed that the heuristic minimizes total flow time of jobs more than dispatching rules up to a certain level of missing operations of jobs in flowshops, after which dispatching rules perform better. The performance of the heuristic and the dispatching rules in terms of minimizing the makespan as a secondary measure is also reported. © 2001 Elsevier Science B.V.

Efficient heuristics for scheduling jobs in a static flowshop with sequence-dependent setup times of jobs are presented in this paper. The objective is to minimize the sum of weighted flowtime and weighted tardiness of jobs. Two heuristic preference relations are used to construct a good heuristic permutation sequence of jobs. Thereafter, an improvement scheme is implemented, once and twice, on the heuristic sequence to enhance the quality of the solution. An existing heuristic, a random search procedure and a greedy local search are used as benchmark methods for relatively evaluating the proposed heuristics. An extensive performance analysis has shown that the proposed heuristics are computationally faster and more effective in yielding solutions of better quality than the benchmark procedures. © 2002 Elsevier Science B.V. All rights reserved.

The purpose of this paper is to identify dimensions of service quality (SQ) and their corresponding measurement variables in the tourism industry by focusing on India, a South Asian destination. The dimensions and the measurement variables have been identified through a detailed review of literature and exploratory research. Service quality in tourism comprises 10 dimensions, namely core-tourism experience, information, hospitality, fairness of price, hygiene, amenities, value for money, logistics, food and security. This study aims to enrich the body of knowledge pertaining to similar work undertaken by researchers in other parts of the world. The growing importance of Asian destinations in the global tourism market in general and emergence of India as a prominent tourist destination in South Asia in particular marks the importance of this study. The proposed framework is expected to equip the tour operators in the western world to better understand the tourism industry in South-Asian destinations. It would also be useful to service-providers for managing other equally important tourist destinations in South Asia and Asia-Pacific regions, which are endowed with similar socio-cultural backgrounds.

The effectiveness of quality management programmes at resulting in enhanced business performance has been a major subject of interest for business and academia alike. In service organizations, customer-perceived service quality is considered as one of the key determinants of business performance. The current study strives to examine the influence of total quality service (TQS) dimensions on customer-perceived service quality. Multiple regression analysis has been used to investigate the relationship between the different dimensions of TQS and the various factors of service quality. The results have indicated that the TQS dimensions, as a whole, are indeed good predictors of service quality. Furthermore, the soft issues of TQS (such as human resource management, customer focus, service culture, employee satisfaction, top management commitment and leadership and social responsibility) seem to be more vital than do hard issues in positively influencing customer-perceived service quality.

Purpose - This research paper aims to identify dimensions of patient-perceived total quality service (TQS) in the healthcare sector. Further, the impact of the dimensions of patient-perceived TQS on patient satisfaction is examined. Design/methodology/approach - A questionnaire has been developed based on an extensive literature review of research in service quality and based on responses of the pilot survey among patients recently discharged from hospital. The instrument thus developed has been examined for its psychometric properties using tests of reliability and validity. Multiple regression analysis has been used to examine the impact of the dimensions of patient-perceived quality on patient satisfaction. Findings - Findings highlight seven distinct dimensions of patient-perceived TQS and the relationships among them. Positive and significant relationships among the dimensions and patient satisfaction have been found. Research limitations/implications - Contribution to research on healthcare services by the development of a comprehensive instrument of patient-perceived healthcare quality. Practical implications - This instrument would enable patients to provide feedback to hospitals regarding the quality of healthcare received by them. Hospitals could use this feedback to analyze their performance, gauge patient satisfaction and benchmark their performance against competitive hospitals. Originality/value - This paper illustrates a comprehensive instrument of patient-perceived healthcare quality. © Emerald Group Publishing Limited.

In the first part of this paper, we consider a kanban-controlled flowshop and present recursive equations for time-tabling of containers in a given sequence. The flowshop is characterized by the following: a production batch of a part-type (or job) divided into kanban lots or containers; production kanbans to control the loading of containers on machines or workstations; withdrawal kanbans to regulate the movement of containers between two consecutive buffer storages; periodic material handling of containers; dual blocking mechanisms operative on workstations and material handling; and sequence-dependent set-up times of containers. Considering different types of problems, recursive equations have been developed for time-tabling of containers in a given sequence. © 2000 Taylor & Francis Group, LLC.