A vehicle routing problem with time windows (VRPTW) is an important problem with many real applications in a transportation problem. The optimum set of routes with the minimum distance and vehicles used is determined to deliver goods from a central depot, using a vehicle with capacity constraint. In the real cases, there are other objective functions that should be considered. This paper considers not only the minimum distance and the number of vehicles used as the objective function, the customer’s satisfaction with the priority of customers is also considered. Additionally, it presents a new model for a bi-objective VRPTW solved by a revised multi-choice goal programming approach, in which the decision maker determines optimistic aspiration levels for each objective function. Two meta-heuristic methods, namely simulated annealing (SA) and genetic algorithm (GA), are proposed to solve large-sized problems. Moreover, the experimental design is used to tune the parameters of the proposed algorithms. The presented model is verified by a real-world case study and a number of test problems. The computational results verify the efficiency of the proposed SA and GA.
In the present competitive world, facility location is an important aspect of the supply chain (sc) optimization. It involves selecting specific locations for facility construction and allocation of the distribution channel among different SC levels. In fact, it is a strategic issue which directly affects many operational/tactical decisions. Besides the accessibility, which results in customer satisfaction, the present paper optimizes the establishment costs of a number of distribution channels by considering their proximity to the stock market of the goods they distribute, and proposes mathematical models for two objective functions using the set covering problem. Then, two objective functions are proposed into one through the ε-constraint method and solved by the metaheuristic Genetic Algorithm (GA). To test the resulted model, a smaller scale problem is solved. Results from running the algorithm with different ε-values show that, on average, a 10% increase in ε, which increases the value of the second objective function - distance covered by customers will cause a 2% decrease in the value of the first objective function including the costs of establishing distribution centers). The repeatability and solution convergence of the two-objective model presented by the GA are other results obtained in this study.
This paper presents an empirical investigation to determine important factors influencing on customer satisfaction in after-sales service network of automotive industry. The study designs two questionnaires, one for measuring the quality of after-sales services and the other for measuring customers’ satisfaction. The study selects a sample of 265 randomly selected customers out of 850 people who received the services from an automotive firm in Iran. Cronbach alpha has calculated as 0.82, which is well above the minimum desirable level. Using Spearman correlation the study has detected a positive and meaningful relationship between services and customer satisfaction (r=0.48, Sig. =0.01), a positive relationship between being responsiveness and customer satisfaction (r=0.51, Sig. =0.01) and finally a positive relationship between speed of operation customer satisfaction (r=0.45, Sig. = 0.01). Moreover, there was a positive and meaningful relationship between cost of services and customer satisfaction (r=0.68, Sig. = 0.01) and a positive relationship between quality of services of after-sales services and customer satisfaction (r = 0.61, Sig. =0.01).
This paper presents an empirical investigation on user’s satisfaction based on the expectation disconfirmation paradigm theory. The study selects a sample of 332 people from 2449 graduate students who were enrolled at the Birjand University. The study uses a questionnaire developed by Isac and Rusu (2014) [Isac, F. L., & Rusu, S. (2014). Theories of user’s satisfaction and the operationalization of the expectation disconfirmation paradigm. Economic series, university of Targu, 2 (1), 82-88.]. Using path analysis, the study has determined that perceived usefulness and personal experience had the highest impact on users’ satisfaction in electronic library usage. In addition, there was a negative relationship between user interface and users’ satisfaction.
Customers are financial and intellectual capital of the firm and its survival and success depend on the attitude and firm performance to its customers. The goal of this article is to study customer satisfaction in Bonny Chow National Distribution Company and offering a model to evaluate customer satisfaction and also to study strength and weakness to improve and facilitate the defects. This study is descriptive, because it collects data and analyzes hypothesis based on expert survey. The questionnaire used in this paper has 10 questions on measure customer satisfaction. The results show that responders were satisfied with the visitors and delivery personnel and they were dissatisfied with the firm. In other words hypothesis 1 and 2 were accepted and hypothesis 3 was rejected.
This paper presents an empirical investigation to study the role of entry into regional markets in fulfilling brand promise. The study designs two questionnaires, one for measuring brand promise and the other for measuring export capabilities, in Likert scale and distributes it among 250 randomly selected producers who were involved in production and development of various products in city of Esfahan, Iran. Cronbach alphas were calculated for brand promise and export capabilities as 0.856 and 0.812, respectively. Using structural equation modeling, the study has detected seven factors including product development, public advocacy, strategic orientation, customer satisfaction, competitive pressures, organizational capabilities and distribution strategies.
Today, many business organizations have replaced product oriented strategies with customer oriented strategies and try to improve the level of their products and services to reach customer satisfaction. Excellent organizations pay especial attention to their customers and always try to do their best to have loyal customers. The purpose of this paper is to investigate the level of customer oriented in an excellence business organization through European Foundation of Quality Management (EFQM) method for one of the biggest Iranian banks in city of Tehran, Iran. The study designs a questionnaire in Likert scale and distributes it among 384 randomly selected customers who do banking business. Cronbach alpha has been calculated as 0.948, which is well above the desirable level. In addition, using t-student test, the study has confirmed that bank enjoyed a satisfactory level of customer oriented.
Recently, the diffusion of the Internet as a retail and distribution channel has undergone a great growth. This paper presents an empirical investigation on the effects of gender differences on online buying. The study explored gender differences among 13 factors concerning the internet buyer. With regard to factors and consistent with Hypothesis and sub hypothesis, differences were detected across genders using t-student tests and the findings were in alignment with the ANOVA test. For data collection and final testing of the E-SAT model a questionnaire was designed and distributed among 100 randomly people who resided in Iran. The analysis show that merchandising, security and company items gained more scores for men than women in online shopping.
This paper presents an empirical investigation to study the effects of service quality on post-purchase intention. The study is applied among some small and medium enterprises (SMEs) in city of Kerman, Iran. There were approximately 300 people working for these units and the study chose 168 people as a sample study. The study used a standard questionnaire consists of 20 questions in Likert scale and distributed it among the sample size. Using structural equation modeling the study has determined that service quality as well as perceived quality influenced positively on customer satisfaction and post-purchase intention.
Nowadays, increasing competition is forcing businesses to pay more attention on customer satisfaction providing strong customer services. Increased competition has also increased marketing activities. This paper presents an empirical investigation to determine important factors influencing purchase decision involvement in food industry in city of Tehran, Iran. The study designs a questionnaire in Likert scale, distributes it among 270 experts in food industry and, using principle component (PCA) analysis, extracts important group of factors. The questionnaire consists of 27 questions, which is reduced to 23 questions because of sensitivity of the PCA to Skewness of data. Cronbach alpha is calculated as 0.81, which is well above the minimum acceptable level. The results indicate that there were four factors including individual differences, product validation, triggers and dependent behavior influencing purchasing decisions.