Modern Research in Decision Making

Abstract Cross docking is a new strategy in supply chain management. In a cross docking system, items move directly from receiving dock to shipping dock, without being stored in the warehouse or distribution center. This paper studies the problem of truck scheduling in a distribution system including multiple cross docks with no intermediate storage. In this model of cross docking scenario preemption of trucks is allowed. Therefore, both inbound and outbound trucks can arrive and move out the distribution center intermittently. In this paper a mixed integer linear programming model has been developed. Moreover, to solve the problem we proposed three metaheuristics algorithm based on tabu search, simulated annealing and genetic algorithm. In this regard, we propose a novel solution encoding scheme for the problem. And the algorithms are tuned by Taguchi method. Using numerical experiments, the genetic algorithm outperforms the other two algorithms Besides.

Abstract One of the main activities of supply chain management is reverse logistics. Reverse logistic encompass all physical activities associated with returned products such as collection, recovery, recycling and disposal. An essential issue of modeling the problem of designing reverse logistic systems is considering the greater number of options regarding the quality of returns and also uncertainty in both quantity and the quality of the returned product. In this study, a two phase fuzzy mixed integer programming is proposed. Because some of parameters are fuzzy, this model design under uncertainty condition. Moreover, the reverse logistics network was developed as a multi-period and multi-product model. The objective function of model is minimizing the total cost of the network. The model is a type of NP-Hard problems which time of solution increases exponentially. Therefore, in this study, we use the genetic metaheuristic algorithm to solve the model.

Abstract In this paper, effective factors on retention and profitability of customers a state owned bank was studied using random forests and regression forests methods. The data was collected form Bank Sepah database. The statistical population consists of 169 corporations holding different types of deposit accounts and utilized one of the different types of services such as sending and receiving payment orders, letters of credit (LC) and foreign exchange facilities during the research period (1389-1391), simultaneously. In this paper, the accuracy of the results of random forests method is compared with the results of logistic regression and bagging methods using area under the Receiver Operating Characteristic (ROC) curve. Furthermore, the results of regression forests method was compared to those of linear regression by calculating Mean Absolute Percentage Error (MAPE). Then, we tried to determine the importance of effective independent variables on dependent ones, i.e. next purchase, activity defection, profit drop and profit continuity using random forests and regression forests. The results show that in the case of offering currency facilities to the customers active in the production fields leading to opening LCs and receiving more payment orders will increase the probability of customer retention. In addition, an increase in the amount of foreign exchange facilities and payment orders offered by banks due to the rate of return of foreign exchange facilities, banking fees, income resulting from issued warranties and selling currencies plays an important role in the profitability of customers.

Abstract Inventory management and production planning are two of necessary tasks for each manufacturing organization. In this paper, a production-inventory model with backlogging is expanded to identify the optimal value of inventory in multi-product organizations when demand is uncertain. The purpose of this problem is maximizing the total company’s profit considering inventory costs such as storage of raw materials and finished goods, backlogging contains both back order and lost sale, and purchasing, which is resulted in a nonlinear model. Also in this paper reworking of defected items and constraints such as finite production rate, warehouse space and capital are considered. The fuzzy set theorem is used to cope with uncertain inputs. To solve the proposed model a combined Honey Bee, Pareto and VIKOR method is applied. Results show that in the similar situations, applying this methodology leads to a maximum profit and minimum cost for manufacturing organizations.

Abstract Public service providers such as state hospitals are one of the major consumers of electrical energy and it is necessary to manage their consumption. In this study, considering consumer preferences and electricity price tariffs, a mathematical programming model has been presented to optimize electrical energy consumption of hospitals. Data for a set of devices utilized by a sample consumer have been gathered. After determining device specifications and consumer preferences, a scheduling model has been implemented. As the objectives of energy management system, three scenarios consist of peak energy minimization (load management), minimization of energy costs and combining the first and the second scenarios have been studied and analyzed. Finally, the energy intensity index has been assessed before and after optimization. The results showed that in the combined scenario that both objectives are considered simultaneously, greater reduction of energy intensity is observed.

Abstract Effective management of projects in research and development centers is one of the key objectives of these centers. Determining the optimal sequence of jobs affect the group productivity, earliness, and tardiness costs. One of the deterministic variants of the problem solving is well-known to be NP-Hard. If random elements are introduced into the problem, the level of complexity becomes higher. Hence, many priority rules have been developed to tackle stochastic job shop scheduling problem. However, to devise a better solution approach, simulation- optimization approach might be used. In this study, a mathematical model is developed for project scheduling with random process times and possible machine breakdowns. Then, a simulation-optimization model is designed to choose among a list of priority rules using Rockwell Arena 14. Finally, a numerical example was used to evaluate the quality of the model. Results show that the rule Longest Processing Time (LPT) yields the lowest total earliness and tardiness costs.

Abstract In today's competitive world, production management practices based on the past method have lost their effectiveness. Since those methods have less integrity in their processesand companies need more integration in all their manufacturing processes. Stable supply chain can be considered as a practical tool that can deliver acceptable performance with a massive sustainability of business engagement to have properperformance for more sustainability of supply chain prescribes competitive priorities can be considered.
The present research aims to determine the competitive priorities in the sustainable supply chain.This research is quantitative based on objective and descriptive-analytic based on method.In this research, we first identify the dimensions of the supply chain which had a hierarchical structure, then by examining the literature, criteria and all the priorities and sub-criteria was identified on the set of companies that is active in the Pars Toosheh company. Then the datawas tested with a combination of multi-criteria decision-making techniques. The results of the research showed that the competitive priorities that the company is competing with in the market and willing to invest more in it are: cost, delivery and quality, andother priorities based on the value we value that we consider for V place in the next priorities.

Abstract In this paper, we consider plant and flower organized exchange market configuration as an optimization problem. Stakeholders in plant and flower organized market problem are supplier, buyer, third-party logistics company, broker and exchange market agent. Plants and flowers are a subset of fresh products and also fresh products are a sub-category of perishable products. In this paper two leader-follower Stackelberg model between supplier and buyer and also between buyer and third-party logistics provider will be proposed. We drive the optimal order quantity, selling and retail price in the first model and optimal transportation price in the second model. At the end, a coordinated and integrated model will be proposed in which all members of the supply chain will try for overall chain profit. Then the expected profits, order quantity, and retail price of the competitive mode and the coordinated model are compared with respect to given numerical example. The results show higher profit and order quantity and lower the retail price in a coordinated mode compared to competitive model.

Abstract One of important factors in management success is reducing production time. In Iran Residential apartment's production process takes considerably more time compared to developed countries like U.S.A and Japan so decrease of process time is one of important problems for construction managers. One of decreasing ways is reducing or elimination of time wastes. The aim of this paper is to identify time waste causes and estimating the amount of these effects. For identifying, after literature review, semi-structured interview and thematic analysis were used and 8 causes were identified that have three factors including presence in executing, direct impact and controllability. These 8 causes are supervisor blockage, lack of materials, lack of equipment, rework, contractors delay, transfer and depot, subcontractors' conflict and doing more activities in site. For estimating the amount of effect, questionnaires were distributed between project managers that had 5 to 7 floor residential apartments and after receiving 214 usable responses, Generalized Regression Neural Network Method were used. The result obtained in this paper is in the presence of all 8 causes in projects, 41.4 percent of executing time is waste and 77percent of this significant amount is because of three causes contractor delay, do more activities in site and rework. These results are appropriate criteria for project manager to make decision about how to dealing with contractors so they can reduce the project duration.

Abstract Effectuation theory by Sarasvathy has helped scholars and practitioners to better understand the logic and process of entrepreneurs’ decision making. Five main principles of this theory show that entrepreneurs are thinking in different way in comparison with traditional managers especially who manage large companies. This paper has a qualitative approach and data gathered through semi-structured interviews with some entrepreneurs from different industries in Iran. The cases are successful entrepreneurial companies. Analysis by causal mapping method demonstrates that Iranian entrepreneurs make decisions in accordance with effectuation principles. They use their available means, affordable loss instead of expected return, partnership, contingencies and prediction instead of control. More analysis show that entrepreneurs make decisions effectually in the beginning stage of the firm but after a while, they shift to causation manner. Finally effectuation logic may cause to gradual or sudden creation of the firm based on available resources.

Abstract Effectuation theory by Sarasvathy has helped scholars and practitioners to better understand the logic and process of entrepreneurs’ decision making. Five main principles of this theory show that entrepreneurs are thinking in different way in comparison with traditional managers especially who manage large companies. This paper has a qualitative approach and data gathered through semi-structured interviews with some entrepreneurs from different industries in Iran. The cases are successful entrepreneurial companies. Analysis by causal mapping method demonstrates that Iranian entrepreneurs make decisions in accordance with effectuation principles. They use their available means, affordable loss instead of expected return, partnership, contingencies and prediction instead of control. More analysis show that entrepreneurs make decisions effectually in the beginning stage of the firm but after a while, they shift to causation manner. Finally effectuation logic may cause to gradual or sudden creation of the firm based on available resources.