PRODUCTION AND OPERATIONS MANAGEMENT
Year:2013 | Volume:3 | Issue:2 (5)|Papers Count:7

Decision making on making/buying problem has always been a challenge to decision makers. In this paper a methodology has been proposed to resolve this challenge. This methodology is capable of evaluating making/buying decision making under uncertainty. For uncertainty, the fuzzy logic and simulation approaches have been used. The proposed methodology can be applied to parts with multi stage manufacturing processes and different suppliers. Therefore this methodology provides a scale for decision making from full outsourcing to full manufacturing and with selecting appropriate supplier.

The purpose of this article is to propose a technique for agility evaluation and ranking production units using verbal variables set and if-then rules. First, organization’s agility level has been evaluated by Fuzzy Agility Index (FAI), and then, production units of the organization have been ranked by Interval Fuzzy ELECTRE technique. By the use of this technique, all of the alternatives have been evaluated based on non-rating comparisons and those of ineffective have been removed. In the next stage, a four dimensional matrix has been proposed as a facilitating tool for decision making process and achievement of managers’ goals. In fact, appropriate strategies have been determined for planning and decision making, according to available conditions and ideal situations.

In this paper, the problem of received order scheduling by a manufacturer, with the measure of maximum completion times of orders, has been formulated and then an analytical approach has been devised for its solution. At the beginning of a planning period, the manufacturer receives a number of orders from customers, each of which requires two different stages for processing. In order to minimize the work in process inventories, the no-wait condition between two operations of each order is regarded. Then, the equality of obtained schedules is proved by machine idle time minimization, as objective, with the schedules obtained by maximum completion time minimization. A concept entitled “Order pairing” has been defined and an algorithm for achieving optimal order pairs which is based on symmetric assignment problem has been presented. Using the established order pairs, an upper bound has been developed based on contribution of every order pair out of total machines idle time. Out of different states of improving upper bound, 12 potential situations of order pairs sequencing have been also evaluated and then the upper bound improvement has been proved in each situation, separately. Finally, a heuristic algorithm has been developed based on attained results of pair improvement and a case study in printing industry has been investigated and analyzed to approve its applicability.

DSL technology services are regarded as a key factor for fast access to data in the large part of population. In this research, a new methodology is presented using fuzzy failure modes and effect analysis and data envelopment analysis to identify the failures of DSL services. The innovation of research includes the application of FMEA in services. Fuzzy logic has been used to contrast with the ambiguity of the evaluations. Therefore, the failure modes in the field of DSL in one of the ISPs have been identified and evaluated by RPN at multiplicative risk. Finally based on the ranking, the most important failures have been identified. The ranking of failure modes indicates that the drop in line speed is the top priority due to high traffic, limited bandwidth of infrastructure companies, viral systems and the problem of internal line.

Target costing by integrating customer requirements, technical attributes and cost information into the product design phase and eliminating the non-value added functions, plays a vital role in different phases of the product life cycle. Quality Function Deployment (QFD) and Value Engineering (VE) are two techniques which can be used for applying target costing, successfully. The purpose of this paper is to propose an integrated model of target costing, QFD and VE to explore the role of target costing in managing product costs while promoting quality specifications meeting customers’ needs. Findings indicate that the integration of target costing, QFD and VE is an essential technique in managing the costs of production process. Findings also imply that integration of the three techniques provides a competitive cost advantage to companies.

In this paper, four different multiple-type dispersion facilities location modeling formulations have been developed, which utilize efficiency measures of Data Envelopment Analysis to find optimal and efficient facility location patterns. While the problems studied previously do not clearly indicate which candidate is elected by a unit, simultaneous DEA approach has been used for analysis. In these models, existing facilities are considered. These models with two objectives, considerabely match the real world problems. Since these four models are multiobjective, a fuzzy goal programming approach has been applied to solve the four problems. In this paper, after introducing the proposed models, an example, with the results of numerical calculations has been presented.

This research based on providing five questions has tried to identify and prioritize the main and sub inhibitors of internet selling boosting in Iran. A mixed method research (QUAN) has been used in this research. In the qualitative phase, individual in-depth interviews have been done with seven e-shop managers. In this phase, 45 detailed inhibitors have been detected. These 45 inhibitors have been categorized in nine sub categories and four main categories. In the quantitative phase a 51-items questionnaires has been designed including six demographical and 45 specialized questions. Findings of the quantitative phase reveal that the main obstacles include legal, cultural, infrastructural and managerial inhibitors. In addition, sub category inhibitors include legal, governmental, telecommunication, society, human resource, transportation, financial and customer related.