## OPSEARCH

OPSEARCH is the official journal of the Operational Research Society of India (ORSI) publishing the research papers in the field of operations research and related fields. It is a quarterly publication (March, June, September and December).

• a) official publication of the prestigious Operational Research Society of India
• b) premier Indian journal in the field of Operational Research

The journal OPSEARCH published by the Operational Research Society of India (ORSI) is a national forum set up with the objective of promoting the education and applications of Operational Research (OR) in day-to-day environment in business, industry and other organizations.

Related subjects » Business & Management - Mathematics - Operations Research & Decision Theory

The latest content available from Springer
1. ### Abstract

Mixed-model assembly line is known to be a special case of production lines where variety of product models similar to product characteristics are assembled. This article addresses available-to-promise (ATP) in mixed-model assembly line sequencing problems in a Make-To-Order environment in two stages. First, the customers are prioritized based on their corresponding profit values and a decision support system for order acceptance/rejection based on ATP is developed. By implementing this concept and developing a mathematical model, delivery quantity and date in a planning horizon are determined based on the inventories in the stock. The second stage is solving a mixed binary mathematical model to sequence accepted orders suitably according to demands due dates that guarantees the orders are not released too late or too early. The problem simultaneously considers following objectives: minimizing the total tardiness and earliness costs based on the determined priority of orders and minimizing the utility work and idle time of workers in the production line. An algorithm based on Lagrangian relaxation is developed for the problem, and tested in terms of solution quality and computational efficiency. To validate the performance of the proposed algorithm, various test problems in small size are solved using the CPLEX solver, and compared with the Lagrangian relaxation method. Finally, the proposed model is solved in large size problems to analyze the model performance. The drawback of the CPLEX is that it could not solve large problem instances in reasonable time. For the small sized problem, there is approximately 1% duality gap for the Lagrangian relaxation method. The maximum duality gap in the Lagrangian relaxation method for the large sized problem is always kept below 4% while the average computing time is very reasonable. Therefore, according to the results obtained from test problems, the developed Lagrangian relaxation method proved to be the suitable method for this problem.

2. ### Abstract

There has been extensive scheduling research relating to use of existing dispatching rules along with/without new dispatching rules and compared their performance behavior in job-shop, flow-shop, open-shop, flexible manufacturing system, and single machine with unit capacity environments using various scheduling objectives. However, it appears that there is no comparative study on analysis of dispatching rules for scheduling bottleneck batch processing machine in discrete parts manufacturing, particularly the diffusion furnace (DF) in semiconductor manufacturing (SM). This study addresses this research issue. For that, this study first, proposes the mathematical models for dynamic scheduling (DS) of DF to optimize the due-date based scheduling objectives: Total weighted tardiness, on-time delivery rate, total earliness/lateness, and maximum lateness. Due to the computational intractability of each the proposed mathematical models for large-scale problem, this study proposes greedy heuristic algorithm (GHA) based on due-date based dispatching rules (DDR). Because, dispatching rules are widely used in the SM industry. Accordingly, in this study twenty variants of GHA-DDR are proposed by considering various due-date based dispatching rules to compare the effects of due-date based dispatching rules in DS of DF. From the series of computational analysis carried out in this study, it is observed empirically that the proposed variants of GHA based on apparent tardiness cost (ATC) and batch ATC (BATC) dispatching rules yield consistently better solution for most of the scheduling objectives considered in this study. This observation is further verified by statistical analysis: Friedman test and Nemenyi multiple comparison test.

3. ### Abstract

The purpose of this study is to measure the financial efficiency of firms considering both input and procurement capital. We propose a new method called three-dimensional data envelopment analysis model and conducted an efficiency analysis of 33 companies in Korea manufacturing auto parts. The results of the study are summarized as follows. Even if the business performance generated by the company is more efficient than the input assets, many inefficient companies exist compared with the procurement capital. Meanwhile, management performance compared with input assets was inefficient; however, there were also companies that were efficient in terms of procurement capital. Therefore, when analyzing the efficiency of a company, efficiency methodology and measurement values that consider both input and procurement capital are needed. This study presents a new measurement methodology based on this point and analyzes the current financial situation of each decision-making unit through return-to-scale analysis and suggests financial improvement direction.

4. ### Abstract

In this paper, the Staff Transfer Problem (STP) in Human Resource Management is addressed as a stable matching problem. Earlier, formulation of this problem was of scheduling/allocation type. Here, the stable matching formulation is completely a new and more practical approach to the problem. This new formulation involves two preference lists: the first list contains the offices/locations preferred by the employees undergoing transfer and the second list contains the employees preferred by the employer of an office/location where those employees want to be transferred. The capacity of an office/location would act as a hard constraint. While matching these two lists, the objective is to maximize the number of transfers and at the same time to stabilize the matching, i.e., to minimize the number of blocking pairs. The resulting STP instance belongs to an instance of Maximum Size Minimum Blocking Pair Stable Matching with incomplete preference list (MAX SIZE MIN BP SMI) and has been proved in this paper to be NP-hard. As the problem is new in formulation, no previous work, method or result is available. There was no preference in selecting meta-heuristics. Among a large number of existing meta-heuristics, some most widely used meta-heuristics, namely, Simulated Annealing, Genetic Algorithms, Tabu Search and some variants of them have been chosen. Based on them four meta-heuristic approaches have been proposed, namely, btSA_match, gtSA_match, GA_match and TS_match. The variants btSA_match and gtSA_match are obtained from modifications made upon Simulated Annealing. EGA_match and TS_match are based on modified Genetic Algorithms and Tabu Search respectively. As there is no previous result in the existing literature, the performance has been compared among these four methods. It is observed that, variants of Simulated Annealing (SA) outperform others w.r.t. the performance metrics. The SA-variant with greedy nature, incorporated with a tabu list (gtSA_match) has shown that the best result on the basis of statistical analysis.

5. ### Abstract

To maximize profit in a competitive market environment, for retailers, it became necessary to optimize preservation, pricing, and marketing strategies together with inventory ordering policies. This study deals with the problem of optimizing price, advertisement frequency, preservation technology (PT) investment and ordering policies simultaneously for non-instantaneous deteriorating items whose deterioration rate can be reduced by investing in PT, while demand depends on both selling price and frequency of advertisement. The supplier allows some credit period to settle the account, and under this policy, three possible cases considered separately. We adopt three-parameter Weibull distribution deterioration and partial backlogs of shortages in a general framework to formulate the model. An iterative algorithm is provided to obtain the optimal solution, then the proposed model is illustrated through numerical examples. The concavity of the total profit function with respect to decision variables shown graphically. Sensitivity analysis has been conducted to investigate the impact of each parameter. PT investment and credit period are beneficial for the retailer, and also can earn more profit through advertisement. Value-added food products, such as bottled fruit juice, soft drinks, packed fruits, bread, cake, processed meat, etc., needs preservation technology and their demand depends on the price as well as marketing. Profit maximization of such items can be studied with the help of new model developed in this paper.

6. ### Abstract

Vogel’s Approximation Method (VAM) is known as the best algorithm for generating an efficient initial feasible solution to the transportation problem. We demonstrate that VAM has some limitations and computational blunders. To overcome these limitations we develop an Improved Vogel’s Approximation Method (IVAM) by correcting these blunders. It is compared with VAM on obtained initial feasible solutions to a numerical example problem. Reduction in the total transportation cost over VAM by IVAM is found to be 2.27%. Besides, we have compared IVAM with each of twelve previously developed methods including VAM on solutions to numerical problems. IVAM leads to the minimal total cost solutions to seven, better solutions to four and the same better solution to the remaining one. Finally, a statistical analysis has been performed over the results of 1500 randomly generated transportation problems with fifteen distinct dimensions, where each of them has 100 problems instances. This analysis has demonstrated better performance of IVAM over VAM by reducing the total transportation cost in 71.8% of solved problems, especially for large size problems. Thus IVAM outperforms VAM by providing better initial feasible to the transportation problem.

7. ### Abstract

This paper deals with the inverse and reverse balanced facility location problems with considering the variable edge lengths. The aim of the inverse problem is modifying the length of edges with minimum cost, such that the difference between the maximum and minimum weights of clients, allocated to the given facilities is minimized. On the other hand, the reverse case of the balanced facility location problem considers the modifying the lengths of edges with a given budget constraint, such that the difference between the maximum and minimum weights of vertices, allocated to the given facilities is reduced as much as possible. Two algorithms with time complexity O(nlogn) are presented for the inverse and reverse balanced 2-facility location problems.

8. ### Abstract

Many organizations utilize information technology to gain competitive advantage. As the need for software increased, the number of software companies and the competition among them also increased. The software organizations in countries like India can no longer survive based on cost advantage alone. The companies need to deliver defect-free software on time within the budgeted cost. This paper is a case study on minimizing the delivered defect density by optimally executing the various phases in software development life cycle process. The implementation of the study on four projects has shown that the delivered defect density can be minimized by executing the software development process with optimum settings suggested by the methodology. The project managers can also utilize the approach to achieve the goals set on other important output characteristics like productivity, schedule, etc.

9. ### Abstract

In this work, we propose a hybrid regression model to solve a specific problem faced by a modern paper manufacturing company. Boiler inlet water quality is a major concern for the paper machine. If water treatment plant can not produce water of desired quality, then it results in poor health of the boiler water tube and consequently affects the quality of the paper. This variation is due to several crucial process parameters. We build a hybrid regression model based on regression tree and support vector regression for boiler water quality prediction and show its excellent performance as compared to other state-of-the-art.

10. ### Abstract

We propose an interior point method to compute solution of linear complementarity problem LCP (qA) given that A is a real square hidden Z-matrix (generalization of Z-matrix) and q is a real vector. The class of hidden Z-matrix is important in the context of mathematical programming and game theory. We study the solution aspects of linear complementarity problem with $$A \in$$ hidden Z-matrix. We observe that our proposed algorithm can process LCP (qA) in polynomial time under some assumptions. Two numerical examples are illustrated to support our result.

11. ### Abstract

Portfolio optimization is defined as the most appropriate allocation of assets so as to maximize returns subject to minimum risk. This constrained nonlinear optimization problem is highly complex due to the presence of a number of local optimas. The objective of this paper is to illustrate the effectiveness of a well-tested and effective Laplacian biogeography based optimization and another variant called blended biogeography based optimization. As an illustration the model and solution methodology is implemented on data taken from Indian National Stock Exchange, Mumbai from 1st April, 2015 to 31st March, 2016. From the analysis of results, it is concluded that as compared to blended BBO, the recently proposed LX-BBO algorithm is an effective tool to solve this complex problem of portfolio optimization with better accuracy and reliability.

12. ### Abstract

The core competency of the healthcare system is to provide treatment and care to the patient. The prime focus has always been towards appointing specialized physicians, well-trained nurses and medical staffs, well-established infrastructure with advanced medical equipment, and good quality pharmacy items. But, of late, the focus is driven towards management side of healthcare systems which include proper capacity planning, optimal resource allocation, and utilization, effective and efficient inventory management, accurate demand forecasting, proper scheduling, etc. and may be dealt with a number of operations research tools and techniques. In this paper, a Markov decision process inventory model is developed for a hospital pharmacy considering the information of bed occupancy in the hospital. One of the major findings of this research is the significant reduction in the inventory level and total inventory cost of pharmacy items when the demand for the items is considered to be correlated with the number of beds of each type occupied by the patients in the healthcare system. It is observed that around 53.8% of inventory cost is reduced when the bed occupancy state is acute care, 63.9% when it is rehabilitative care, and 55.4% when long-term care. This may help and support the healthcare managers in better functioning of the overall healthcare system.

13. ### Abstract

Analytic hierarchy process (AHP) is a widely used multicriteria decision making method. Chang’s extent analysis method (EAM) is appeared as a very popular fuzzy AHP approach. The aim of this paper is to generalize the EAM in intuitionistic fuzzy settings for effective modeling of imprecision and uncertainty inherent in nature. In this paper, special triangular intuitionistic fuzzy degree of possibility is defined for comparing two or more triangular intuitionistic fuzzy numbers (TIFNs) and some relevant theorems are introduced generating intuitionistic fuzzy numbers as weights of criteria or performance scores of alternatives. Based on TIFNs, a conversion scale for linguistic variables is proposed for generating a triangular intuitionistic fuzzy preference relation. The EAM is then generalized in intuitionistic fuzzy settings by proposing generalized intuitionistic fuzzy EAM using TIFNs and its arithmetic for deriving crisp priority vector from the triangular intuitionistic fuzzy preference relation. The advanced approach is validated through two numerical examples.

14. ### Abstract

Banks are the financial intermediaries and important means for the advancement of economies. In the cutthroat competitions, the increase in market shares is a matter of concern for all. Banks are expected to increase their efficiency to boost competitive capacity, which also helps the Decision-maker to know about grey areas for development. Therefore, performance measurements of efficiency calculation, by using different methods are the concern for research across the world. This paper tries to use the combination of AHP, TOPSIS, and Grey Relational Analysis for efficiency calculation of different public sector banks in India and finally, results were compared. AHP is used to determine the weight criteria and Grey Relational Analysis and TOPSIS are used to rank the bank performances. The proposed method of this study used various inputs and outputs criteria which were taken from various banks annual reports. Descriptive statistics and correlation matrix were used to test the validity of the criteria. The findings reveal that banks which are considered as efficient are close to relative closeness to the ideal solution, expose an alternative ranking of the banks, present research also provides better insight to focus on the area of improvement in comparison to others banks. The Comparative result shows both models have the almost same interpretation. Little deviation in their ranks is due to methodological differences. The proposed research will provide a framework for further applications and both approaches will help decision maker of Indian Public sector banks to find optimal solutions to the complex problems by assessing various alternatives.

15. ### Abstract

The distance measure based on hesitant fuzzy sets is an effective tool in the field of treating similar objects where it distinguishes the difference between two objects. Several distance measures have been proposed so far by different researchers. In this paper, we have proposed modifications in the existing distance measure so that some situations in real life conditions can be handled easily with the proposed distance measure whereas the existing one can not. Finally, the validity and applicability of the proposed distance measure is discussed with some existing examples.

16. ### Abstract

The present study analyzes a production-inventory system with hybrid carbon regulation policy. This hybrid carbon policy is a combination of carbon tax and cap-and-trade policies. It considers a single item that can be produced in different qualities. Production cost, setup cost, amount of emissions and the demand rate depend on the quality. The demand rate for each quality is price sensitive. Emissions occur from three sources—setup, production process and stock holding. The firm can invest on green technologies in each emission source separately to reduce emissions. This model considers profit maximization policy. The managerial problem is to select the profit-maximizing quality for production, and to find the optimum values of the production run time, green investments and the selling price. An algorithm is provided to solve the model. The model is illustrated by a numerical example. Sensitivity analysis is also performed.

17. ### Abstract

The production of sugar in plant consists of procedural steps, each step consisting of various sub-systems. Milling plant is the most important sub-system of a sugar manufacturing plant. The equipment availability in milling plant is a big issue as it has direct bearing on total production cost. Intelligent and effective maintenance planning can decrease total production cost and contribute in achieving strategic goals of sugar manufacturing plant. The objective of this paper is to generate and maintain reliable and exhaustive database of agile maintenance attribute for selection of effective maintenance strategy in milling plant of sugar industry. The database of eighty-eight (88) agile maintenance attributes were formed, out of which twenty-six (26) pertinent attributes relevant to the system under study. PM, PDM, CM, CBM and RCM strategies are selected for prioritization respectively. The proposed framework prioritizes and selects maintenance strategy by fuzzy integrated MADM approach. The fuzzy TOPSIS, fuzzy graphical and fuzzy digraph and matrix approach were used for decision making. The results from analysis were compared for better understanding and effective maintenance strategy selection. Proactive maintenance approaches of PDM RCM and CBM were identified as best alternative by different methods. Further, limitations due to uncertainty and vague expert judgement were eliminated in analysis by integrating fuzzy methodology. The novelty of study is selection of optimum maintenance policy based on agile maintenance attributes using proposed framework. The proposed framework will act as decision support system for efficient planning of maintenance activities using exhaustive database of agile maintenance attributes and selecting effective maintenance strategy.

18. ### Abstract

This work begins with the understanding of the fundamentals of blood banking by analyzing various aspects of its supply chain and then examines the current scenario of blood shortage in India. A mathematical model is proposed to curb the mismatch between surplus and shortage of blood units at blood banks. This proposed model has three main echelons: forecast the demand of blood units at the blood bank; determine the optimal allocation of units from blood banks with surplus to a blood bank with shortage; select the optimal route for the delivery of the allocations. Further, it has been shown empirically with the previous years’ data that SARIMA model is a very efficient forecasting methodology in blood supply management.

19. The editor has retracted this article [1] because it has significant overlap with a work published by Sudhesh and Azhagappan [2] and is therefore redundant. The authors do not agree to this retraction.