Journal of Advances in Industrial Engineering
Volume:49 Issue: 1, 2015

Proper inventory control policy and the optimal price for the items has always been one of the main topics of scientific research and industry. On the other hand, there are many products in the market witch are classified as deteriorating items. Therefore the problem of determining optimal price and optimal inventory policy for this type of items is very important. In this paper a 3 echelon supply chain consisting of a manufacturer, a distributor and a retailer is considered. There is only a single type of item with constant deterioration. Demand is deterministic and replenishment is instantaneous. The purpose of this study is to increase the total profit by determining the optimum values of the product price (p) and ordering cycle (T) of distributor. Since the products are deteriorating, some part of the initial stored inventory is lost. Therefore, distributor disposes the spoiled items and replaces them with the same amount of sound items. The replacement in the storehouse of the distributor is also instantaneous. Finally, numerical examples are presented to elaborate the model and sensitivity analysis is performed on the values of some parameters.

Responsibility in demand networks is one of the most important measures of performance. The concept of agility and flexibility in service and production. Variety and changes in demand need more flexible network design that can cope with potential shortage and delay. This paper presents new mathematical model to optimize the design of demand network when there are highly variable demands. It also takes security measures into the accounts that lead to the less discoverable nodes and centers in the network. The final mixed integer linear programming model has been applied on a real system and the results have been discussed at the end of the paper.

Nowadays, close competition and high cost of production cause the loss reduction and waste recovery to be one of the most concern of industrial and production companies and factories. For this, managers are looking for new methods to reduce the defect in the product line of the factories. Image processing and machine monitoring systems are technologies used in different fields of military, physician, agriculture, industry, etc. Purpose of this study is to use an image processing model to recognize the defect in the product line. As a case study, oil bottles produced by Shiraz Vegetable Oil Company are used. Input data to the program is the images of the intact and defected oil bottles and output is the final judgment of program about the correctness of the bottles. Image processing is performed using software MATLAB. In this study two different procedures are used to identify the intact and defected oil bottles. The first theory is based on the comparison of the area of intact and defected bottle images and the second theory compares the ratio of the height to the sum of some widths for two different images. Second theory uses edge function algorithm and the result obtained from this theory is more optimize with respect to the first theory. This theory is programmed without using the image of an intact object as reference image. This is one of the advantages of second theory with respect to the first one; because a small defect in reference image of the first theory can strongly affect the results. This research is also, consist of two recommended theories. The first theory is based on a reference point in the image and summarizing some of the distances from the edge of the bottle to the reference point. Such, that acceptable results can be obtained by comparing the summarized distances in the intact and defected bottle. The second recommended theory is based on the comparison of the center of area in the intact and defected bottles.

Laparoscopy or minimally-invasive surgery is a surgical technique in which the surgical operations are performed via a few small incisions. This kind of surgery has fewer complications over open surgery. Finding methods for shortening the time of laparoscopic surgeries can improve operating room efficiency. An approach to shortening the time of laparoscopic surgeries is identifying the interruptions in these surgeries and preventing from their occurrence or reducing the potential of occurrence of the identified interrupt causes. In this paper, the interrupt causes of laparoscopic surgeries are prioritized based on the identified causal relations between interrupt causes. Research population is the laparoscopic surgeries performed in Hasheminezhad kidney center in May-June 2013. For this purpose, 25 laparoscopic surgeries are observed in this hospital in this time interval. Causal relations among interrupt causes are identified from the gathered data. The main causes are identified and ranked based on Fuzzy TOPSIS method. For prioritizing the interrupt causes, frequency of occurrence, average length, severity degree, the potential of reducing interrupt occurrence and the potential of preventing interrupt occurrence are considered.Experimental results show that the most important interrupt causes in laparoscopic surgeries are staff shortage or multi-tasking staff, foggy lens, unavailable surgical instruments, dirty lens and finally low-experienced staff. Moreover, sensitivity analysis on criteria weighting show that the mentioned interrupt causes are the five most-important interrupt causes in more than 80% of the evaluated scenarios.Preventing the occurrence of the most-important interrupt causes can improve the surgical time. If it is not possible, reducing the average length of interrupts caused by the identified main causes can be considered for improvement of the operating room efficiency.

In this paper, a comprehensive and simplified model for industries’ performance evaluation and performance measurement is offered. We use the balanced scorecard as a framework for the continuous DEA models. This means that we used four output-oriented DEA models with variable returns to scale, for each of the four aspects of BSC and used the indicators tailored to each BSC aspects as inputs and outputs of DEA models. In this model we use the bargaining game theory to show the impact of bargaining power of units in the competitive environment. Thus,we offer a holistic approach to evaluating and improving the performance of the industries in a competitive environment. Finally, by providing a case study of 17 cement companies of the holding of Shasta (Social Security Investment Company) to run the model and offer solutions to improve the poor performance of units. Results imply the power of the proposed model in evaluating the overall performance of the units and a key advantage over previous models.

In today’s growing competitive environment, supply chain management has been widely focused by firms as a critical issue. Consequently, the organization’s activities are influenced in order to achieving quality improvement, cost reduction and customer satisfaction in production process. Recently, pollution and greenhouse effects have focused the researchers’ attention on planning and executing networks in which environmental problems and economical aspects are considered simultaneously. In this paper, a multi-layer, multi-product and multi-period supply chain network with product return will be studied. The operation risks are assumed as failures occurring in supplier and plant segments. The mathematical modeling will select the best suppliers according to selling price, transportation costs and the average of deficiency. Uncertainty is considered by means of fuzzy approach. The proposed multi-objective fuzzy model is first defuzzified using Jimenez technique and then it is solved by TH method. As the supply chain problems are determined as NP-Hard problems, in this study we took advantage of NSGA II in a large-scale case.

In classic inventory control system, we assume that purchasing cost should be paid at time of delivery. But sometimes in order to encourage retailer to increase his order, postpond payment is provided by supplier as an incentive policy for retailer. In this paper a periodic inventory control model is invetigated in which the period between two consecutive replenishmnet is a random variable. In fact the economic order quantity model under stochastic period lenght and postpond payment is developed. In this paper the concavity of profit function is prooved and situation under which the profit function of retalier is maximized, is determined. The aim of this researchis to determine the the maximum level of inventory such that the total profit is maximized. In continue in order to describe the model numerical examples and sensitivity analysis are introduced.

One of the most important measures needed to be done in times of crisis is to optimize the allocation and distribution of resources among individuals. Time is a critical factor effective to increase the number of people rescued by the relief activities.In this paper, we present a relief vehicle routing model in the affected area which uses covering tour approach to reduce total response time. Also, it is too difficult to determine the real amount of demands for essential commodities, e.g. first-aids, drinking water, etc. Therefore, we consider a fuzzy chance constrained programming model based on the fuzzy credibility theory. In order to validate the model, several numerical examples are solved using branch and bound A metaheuristic algorithm based on harmony search algorithm incorporated with stochastic simulation is developed and proposed to solve the problem. The results of the proposed algorithm compared with the results of the exact method shows 1% error for the algorithm. This indicates the efficiency of the proposed algorithm. To evaluate the proposed algorithm on a large scale, the results of the algorithm, has been compared with the results of GRASP method.The experimental results have shown that the proposed algorithms have appropriate performance in a reasonable time.

Closed-loop supply chain network (CLSCN) design aims at incorporating environmental considerations into the traditional supply chain design by including recycling, disassembly and reuse activities. In a CLSCN, the environmental considerations can also be facilitated by resorting to environmentally friendly materials and enhancing product reuse through the design of an appropriate product recovery, disassembly, and refurbishing network. In this design process, tradeoffs must be made to accommodate the profit and greenness maximization objectives. In this paper, a bi-objective binary integer programming model is developed and solved for a forward/reverse logistic network including three echelons in forward direction (namely, suppliers, assembly centers and customer zones) and two echelons in the reverse direction (namely, disassembly and e-recycling centers). A set of Pareto optimal solutions is obtained to show the trade-off between the profit and the greenness objectives. Some useful managerial insights are developed through various experiments.

Each year many large scale national projects face execution problems. In this regard, risk management can play a significant role in identifying and taking proper measures. In this research, using Project Management Body of Knowledge (PMBOK), a risk management procedure has been designed and implemented in transmission and high distribution power lines of Khorasan Regional Electric Company. First, using the results obtained from field studies and other information gathering tools, different kinds of risks in transmission and high distribution power lines have been identified. Next, risks analysis have been carried out based on probability of occurrence, ease of detection, manageability as well as their impact on project goals. The rate of goals achievement was taken into account by three criteria including time, cost and quality of execution. This followed by classification of the risks, through risk breakdown structure, and then their prioritization. The results show that budget shortage, sanctions issues, improper selection of project team, have been the main risks in the projects considered in this research. The proposed approach in this study, with minor modifications, may be employed to manage the risks in other large scale national projects.

Performance of a supply chain highly depends on its suppliers and therefore, appropriate selection of them is of great importance. This paper presents an integrated model of an MCDM method and a mathematical programming in order to select suppliers and determine lot sizes in the supply chain. The proposed framework comprises two main sub-models; the qualitative sub-model seeks to evaluate the suppliers by means of Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). Then, in the quantitative sub-model, a mixed integer nonlinear program is proposed in order to determine the optimal orders allocated to each supplier. Fuzzy multi-objective method (TH) is used to tackle complexity of the model. The most notable features of the proposed model is considering different quality levels and related defective rates as well as partial supplier switch. Finally, to demonstrate applicability of the proposed model and superiority of the developed algorithm, several problem instances are generated and solved.

Increasing of the distribution efficiency is one of the most objectives of an integrated logistic system developed as a new management philosophy in the past few decades. The problem is examind in two parts: facilities location problem (FLP) for long policies and vehicle routing problem (VRP) to meet the customer demand. These two components can be solved separately; however, this solution may not be the optimum solution of the original problem. Hence, in this paper, facilities location and vehicle routing problems are considered simultaniously to visit the facilities that should be serviced. Due to the complexity of the integrated problem in large sizes, a hybrid imperialist competitive algorithm (ICA) is proposed. Furthermore, to show the efficiency of the proposed hybrid ICA, a number of test problems in small and large sizes are solved. Finally, the obtained results are evaluated with the results obtained by CPLEX. Finally, the conclusion is provided.