A hybrid Tabu search-simulated annealing method to solve quadratic assignment problem

Quadratic assignment problem (QAP) has been considered as one of the most complicated problems. The problem is NP-Hard and the optimal solutions are not available for large-scale problems. This paper presents a hybrid method using tabu search and simulated annealing technique to solve QAP called TABUSA. Using some well-known problems from QAPLIB generated by Burkard et al. (1997) [Burkard, R. E., Karisch, S. E., & Rendl, F. (1997). QAPLIB–a quadratic assignment problem library. Journal of Global Optimization, 10(4), 391-403.], two methods of TABUSA and TS are both coded on MATLAB and they are compared in terms of relative percentage deviation (RPD) for all instances. The performance of the proposed method is examined against Tabu search and the preliminary results indicate that the hybrid method is capable of solving real-world problems, efficiently

A binary particle swarm optimization algorithm for ship routing and scheduling of liquefied natural gas transportation

With the increasing global demands for energy, fuel supply management is a challenging task of today’s industries in order to decrease the cost of energy and diminish its adverse environmental impacts. To have a more environmentally friendly fuel supply network, Liquefied Natural Gas (LNG) is suggested as one of the best choices for manufacturers. As the consumption rate of LNG is increasing dramatically in the world, many companies try to carry this product all around the world by themselves or outsource it to third-party companies. However, the challenge is that the transportation of LNG requires specific vessels and there are many clauses in related LNG transportation contracts which may reduce the revenue of these companies, it seems essential to find the best option for them. The aim of this paper is to propose a meta-heuristic Binary Particle Swarm Optimization (BPSO) algorithm to come with an optimized solution for ship routing and scheduling of LNG transportation. The application demonstrates what sellers need to do to reduce their costs and increase their profits by considering or removing some obligations

Evaluating innovation capabilities of real estate firms: a combined fuzzy delphi and dematel approach.

Due to strong competition, numerous technology advancements and the monetary policy of the government, the survival of Indian real estate firms now depends on their capacity to measure their existing innovation capabilities, rebuild them and adopt new ones. The aim of this study is to evaluate the technology and human resources innovation capabilities of Indian real estate firms by applying fuzzy Delphi and DEMATEL techniques. After identifying the innovation capabilities through an extensive literature review, a questionnaire is designed based on fuzzy linguistic scales to manage any vagueness of information received. Data has been collected from experts in the field, with capabilities then finalized by using a fuzzy Delphi method. To establish cause-effect relationships among capabilities, a DEMATEL method is applied to the data collected from a second questionnaire. Analysis of the data divides capabilities into two groups i.e. cause and effect. The results show that innovation management, robustness of product and process design capability, strategic planning and knowledge resources fall in the cause group; these are critical findings given the effect on the other capabilities. The study outcomes can help real estate firms to enhance their capabilities with the proposed model providing guidelines and direction in this regard.N/

Performance evaluation of services quality in higher education institutions using modified SERVQUAL approach with grey analytic hierarchy process (G-AHP) and multilevel grey evaluation

In today’s climate of fierce competition, there is a necessity to pay especial attention on customer demands either in manufacturing or service sector. Managers in service sector are under pressure in terms of environmental factors, they focus on customers’ satisfaction and this has led to the continuous improvement in the performance of service organizations. Meanwhile, customers’ expectations should be properly understood and measured. There have been various efforts to measure the quality of services using the SERVQUAL model. In this study, we try to investigate the concepts and factors influencing the quality of services according to modified SERVQUAL model and then utilize the proposed model of Grey Analytic Hierarchy Process (G-AHP) and Multilevel Grey Evaluation in order to evaluate the quality of services in the framework of Grey Systems Theory (GST). In order to propose our method, we will conduct a case study of the performance of service quality in higher education institutions of Isfahan-Iran

Investigating the role of social media in polio prevention in India: a Delphi-DEMATEL approach

Abstract Purpose- This study aims to evaluate the role of social media (SM) tools in the polio prevention in an Indian context, using a hybrid Delphi-DEMATEL approach. Design/methodology/approach- A preliminary list of suitable evaluation criteria was derived from an extensive literature review. Ten experts were then contacted to collect data and finalize the most prominent criteria using the Delphi method. To establish cause-effect relationships among the criteria, further data were collected from twenty-one experts. The decision-making trial and evaluation laboratory (DEMATEL) method was applied to process and interpret the data collected. Findings- The analysis grouped criteria into two sets, i.e. cause and effect. The results show that awareness of social cause and government utilization of resources fall into the cause group; these elements are critical since both directly affect the remaining criteria. These outcomes can help government and businesses to utilize SM for public health surveillance, e.g. to promote schemes/initiatives through sites concerning polio or related health issues. Practical implications- The findings of this research are useful for governments and individual companies to conceive their marketing initiatives akin to polio prevention issues using SM. Originality/value- Despite the emergence of SM, there has been little discussion in existing literature on their role for polio prevention; however, measuring such role could be useful in practice, to help decision makers (DMs) exploiting the potential of SM in the healthcare context. To fill this gap, this study aims to measure the role of SM in polio prevention in the Indian context and to create a cause-effect evaluation model. Using an integrated Delphi-DEMATEL framework for decision-making in the healthcare context is another novelty of this study.N

An integrated grey-based multi-criteria decision-making approach for supplier evaluation and selection in the oil and gas industry

Purpose The oil and gas industry is a crucial economic sector for both developed and developing economies. Delays in extraction and refining of these resources would adversely affect industrial players, including that of the host countries. Supplier selection is one of the most important decisions taken by managers of this industry that affect their supply chain operations. However, determining suitable suppliers to work with has become a phenomenon faced by these managers and their organizations. Furthermore, identifying relevant, critical and important criteria needed to guide these managers and their organizations for supplier selection decisions has become even more complicated due to various criteria that need to be taken into consideration. With limited works in the current literature of supplier selection in the oil and gas industry having major methodological drawbacks, the purpose of this paper is to develop an integrated approach for supplier selection in the oil and gas industry. Design/methodology/approach To address this problem, this paper proposes a new uncertain decision framework. A grey-Delphi approach is first applied to aid in the evaluation and refinement of these various available criteria to obtain the most important and relevant criteria for the oil and gas industry. The grey systems theoretic concept is adopted to address the subjectivity and uncertainty in human judgments. The grey-Shannon entropy approach is used to determine the criteria weights, and finally, the grey-EDAS (evaluation based on distance from average solution) method is utilized for determining the ranking of the suppliers. Findings To exemplify the applicability and robustness of the proposed approach, this study uses the oil and gas industry of Iran as a case in point. From the literature review, 21 criteria were established and using the grey-Delphi approach, 16 were finally considered. The four top-ranked criteria, using grey-Shannon entropy, include warranty level and experience time, relationship closeness, supplier’s technical level and risks which are considered as the most critical and influential criteria for supplier evaluation in the Iranian oil and gas industry. The ranking of the suppliers is obtained, and the best and worst suppliers are also identified. Sensitivity analysis indicates that the results using the proposed methodology are robust. Research limitations/implications The proposed approach would assist supply chain practicing managers, including purchasing managers, procurement managers and supply chain managers in the oil and gas and other industries, to effectively select suitable suppliers for cooperation. It can also be used for other multi-criteria decision-making (MCDM) applications. Future works on applying other MCDM methods and comparing them with the results of this study can be addressed. Finally, broader and more empirical works are required in the oil and gas industry. Originality/value This study is among the first few studies of supplier selection in the oil and gas industry from an emerging economy perspective and sets the stage for future research. The proposed integrated grey-based MCDM approach provides robust results in supplier evaluation and can be used for future domain applications

Analyzing the Operations Strategies of Manufacturing Firms Using a Hybrid Grey DEA approach – A case of Fars Cement Companies in Iran

In competitive markets, the operations strategies of companies are normally formulated based on their competitive advantages. An effective operations strategy should maintain and improve competitive advantages based on the capabilities of the corporate operations resources. Considering the market requirements and the operational performance of the rivals is the key for success and survival of a company in the competition. Therefore, recognizing where a company stands in comparison with its rivals and adopting the appropriate operations strategy plays vital roles in the success of companies. This paper proposes a method for comparing and ranking operations strategies of companies based on the concept of efficient frontier using data envelopment analysis (DEA) in grey environment. In the aforementioned method, DEA is used to evaluate the efficiency of operations strategies of manufacturing firms. Also, grey theory is used to support the uncertainty of the experts’ opinions regarding the inputs and outputs of the DEA model. Then the respective units are ranked, and analyses are performed. The proposed approach is applied for the entire nine cement factories of Fars Province in Iran, and the units are ranked, respective analyses are presented regarding the efficient and inefficient units

Supply chain resilience assessment: A grey systems theory approach

Supply chain resilience (SCR) is a crucial property for having efficient supply chain network in any successful enterprise. Due to the increasing uncertainty in the today's business world and the widespread recognition of the grey theory as an effective way to deal with uncertain situations, this study presents a method for measuring SCR based on a grey system theory approach. For this purpose, a case study is carried out in a cement production company, located in Iran. Results revealed that distribution problems and supply limitations are the most serious vulnerabilities threatening the abovementioned company. Therefore, the cement company must make a plan to improve the effectiveness of its SCR by selecting an appropriate set of capabilities including effectiveness, resilience in supply, and flexibility in order fulfillment which are identified as three important capabilities of the case company's supply chain