From a wide variety of queuing models, the finite-capacity queuing models are the most commonly used, where arrival and service rates follow an exponential distribution. Based on two criteria of system cost and expected degree of customer satisfaction, the present study defines a new productivity rate index and evaluates the optimization of a queuing model with finite capacity. In queuing models, obviously, as the number of servers increases, the length of waiting lines decreases, the expected degree of customer satisfaction enhances, and obviously the system cost increases. This study deals with the mathematical relationships involved in the computations of these two criteria, and proposes a novel approach to determine an optimal number of servers by considering a decision-maker & apos; s priority and establishing a trade-off between criteria.

In this article, a framework is proposed to define and identify knowledge work intensity in jobs, quantitatively. For determining the Knowledge Work Intensity Score (KWIS) of a job, it is supposed that the job comprises some tasks and KWIS of the job is determined based on knowledge intensity of these tasks. Functional Job Analysis (FJA) method is applied to determine tasks of jobs and then Task’s Knowledge Intensity Score (TKIS) is computed by using Fuzzy integral method. Besides, importance weight and time weight of tasks are determined by utilizing appropriate methods. Finally, KWIS is calculated by a formula composed of tasks’ TKISs and the weights. For evaluating applicability of the framework, it is applied to calculate KWISs of two jobs (Deputy of Finance and service, Laboratory technician).

Differential Search (DS) algorithm is a new meta-heuristic for solving real-valued numerical optimization. This paper introduces a new method based on DS for solving Resource Constrained Project Scheduling Problem (RCPSP). The RCPSP is aimed to schedule a set of activities at minimal duration subject to precedence constraints and the limited availability of resources. The proposed method is applied to PSPLIB case studies and its performance is evaluated in comparison with some of state of art methods. Experimental results show that the proposed method is effective. Also, it is among the best algorithms for solving RCPSP.

In the context of supply chain management, supplier selection plays a key role in reaching desirable production planning. In today & apos; s competitive world, many enterprises have focused on selecting the appropriate suppliers in an attempt to reduce purchasing costs and improve quality products and services. Supplier selection is a multi-criteria decision problem, which includes different qualitative and quantitative criteria such as purchase cost, on time delivery, quality of service, etc. In this study, a fuzzy multi-objective mathematical programming model is presented to select appropriate supplier and assign desirable order to different supplies. The proposed model was implemented for an organization by considering 16 different scenarios and the results are compared with two other existing methods.

Distribution and optimum allocation of emergency resources are the most important tasks, which need to be accomplished during crisis. When a natural disaster such as earthquake, flood, etc. takes place, it is necessary to deliver rescue efforts as quickly as possible. Therefore, it is important to find optimum location and distribution of emergency relief resources. When a natural disaster occurs, it is not possible to reach some damaged areas. In this paper, location and multi-depot vehicle routing for emergency vehicles using tour coverage and random sampling is investigated. In this study, there is no need to visit all the places and some demand points receive their needs from the nearest possible location. The proposed study is implemented for some randomly generated numbers in different sizes. The preliminary results indicate that the proposed method was capable of reaching desirable solutions in reasonable amount of time.

The bullwhip effect is a phenomenon in forecast-driven distribution channels, which is associated with a trend of larger and larger swings in inventory in response to changes in demand, as we look at firm further back in the supply chain for a particular product. This paper deals with the bullwhip effect in a multi-echelon multiple products supply chain with correlated market demands. The downstream retailer procures products from an un-capacitated upstream supplier to meet the correlated market demands of multiple products. This paper proposes a new method based on demand forecasting technique and uses a simple moving average to eliminate the bullwhip effect, which is proved to be effective under some circumstances.

This paper examines the effect of the service brand on the customer value–loyalty process. The study includes the traditional effect of brand image plus three additional influences, which reflects the broader service perspective including company image, employee trust, and company trust. Using survey data of a sample of 385 bank customers, the analysis indicates there is a direct influence of some of the perspectives of the brand on customers & apos; perceptions of value. The results indicate that brand image, organization image, trust to firm influence positively on quality of services. In addition, brand image, organization image, quality of services and trust to firm influence on customer’s perspective where quality of services maintains the lowest impact and corporate image has the highest impact on customer’s perspective.

This paper investigates consumer involvement profile among people who intend to purchase mobile devises. The study considers the effects of various factors influencing on purchase intention including consumers’ personal characteristics such as age, gender, income as well as some external factors including advertisement. The study uses a questionnaire in Likert scale, originally developed by O’Cass (2000) [O’Cass, A. (2000). An assessment of consumers & apos; product, purchase decision, advertising and consumption involvement in fashion clothing. Journal of Economic Psychology, 21, 545-576.]. The questionnaire has been distributed among 385 people, randomly who purchased mobile devices from a mall in city of Tehran, Iran. Using Pearson correlation test, the study has concluded that oral advertisement as well as consumer purchase involvement have positive and strong relationship with consumer’s purchase intention. In terms of age, people aged 20-30 maintained the highest purchase intention. In addition, in terms of gender, men had more purchase involvement than women did.

This paper investigates the role of export competitive advantage on export performance in food industry. The proposed study designs a questionnaire in Likert scale and distributes it among 280 randomly selected experts in food industry and Cronbach alpha has been calculated as 0.827. The study has applied factor analysis to find important factors influencing export performance. Kaiser-Meyer-Olkin Measure of Sampling Adequacy and Bartlett & apos; s Test of Sphericity have been performed to validate the results and they both validated the questionnaire. The results of the survey have determined six effective groups including product development, e-commerce, marketing planning, organizational performance, competitiveness and supply chain management.

This paper investigates the effects of three components of organizational justice on development e-banking in one of Iranian banks. The proposed study uses two questionnaires, one for measuring the effects of organizational justice and the other for e-banking in Likert scale. Cronbach alphas for organizational justice and e-banking are calculated as 0.831 and 0.749, respectively. The study has been implemented among 385 regular customers of an Iranian bank. Using Spearman correlation ratio as well as stepwise regression analysis, the study has detected that two components of organizational justice including distributive justice and procedural justice influence on e-banking, positively.