Stochastic multi-period multi-product multi-objective Aggregate Production Planning model in multi-echelon supply chain

In this paper a multi-period multi-product multi-objective aggregate production planning (APP) model is proposed for an uncertain multi-echelon supply chain considering financial risk, customer satisfaction, and human resource training. Three conflictive objective functions and several sets of real constraints are considered concurrently in the proposed APP model. Some parameters of the proposed model are assumed to be uncertain and handled through a two-stage stochastic programming (TSSP) approach. The proposed TSSP is solved using three multi-objective solution procedures, i.e., the goal attainment technique, the modified ε-constraint method, and STEM method. The whole procedure is applied in an automotive resin and oil supply chain as a real case study wherein the efficacy and applicability of the proposed approaches are illustrated in comparison with existing experimental production planning method

A Robust Two-Stage Stochastic Location-Routing-Inventory Model for Perishable Items

The aim of this study is to develop a robust two-stage stochastic location-routing-inventory model for perishable items. The proposed model is implemented in a two-stage structure. The first-stage decisions determine the establishment of distribution centres and the second-stage decisions identify the other variables of the problem. In order to reduce the effect of different scenarios on the outputs of the problem, the two-stage model is developed to a robust model. Two variability criteria called \u27Partial Lower Deviation from Mean\u27 (PLDM) and \u27Partial Lower Deviation from Target\u27 (PLDT) are considered for the problem. This robust model can manage the variability of different scenarios considering the variability needed for the problem. The summary of the results of the models indicate that the supply cost, the setup cost, the vehicle supply cost, and the production cost comprise 55%, 28%, 3%, and 14% of the total costs of the supply chain, respectively. Similarly, the ratio of net profit margin to the total revenue of the supply chain derived from the division of the objective function by the revenue function is 15%. Among free, fresher first, older first, and mixed policies, the free policy provides the decision maker with more profit than the other three policies since it imposes less constraints on the model

Social Innovation: Towards a Better Life after COVID-19 Crisis: What to Concentrate On

We know that saving lives of people is the most important issue during COVID-19 crisis, but we should not forget that due to this crisis, the quality of life for many people will change and new social needs will appear and we must be prepared for that. The main purpose of this research is to find out the areas, which are the most affected ones by the pandemic and have a direct impact on citizens’ lives. This research is a quantitative study, which plans to use the opinions of business and management graduates in Iran to present the status of affected fields of better life index by COVID-19 crisis. A fuzzy TOPSIS method is used here to do this ranking. This research has ranked the most affected indicators of better life index by COVID-19 pandemic. In addition, the profile of this impact including the indicators of better life index and their change is also presented in this research. We found out that most affected indicators are Income, jobs, health, life satisfaction and education, respectively. The output of this research can be used for policy makers to start providing support on policies, infrastructures and social innovations on the most affected dimensions in order to reduce the impact of this pandemic on citizens’ everyday life and their quality of life. Also using fuzzy TOPSIS in recognizing the most affected dimensions of quality of life of citizens is a theoretical implication of this research for similar ideas of future researchers. This study is a pioneer in investigating the effects of COVID-19 pandemic on dimensions of life quality of citizens. Also linking the better life index, as a comprehensive index, which has a direct impact on people’s lives to social innovation is another novelty of this research. As it opens a new window for social innovators to know how they can use their innovation capacity to have higher impact on society by shedding light on the main challenges occurred in people’s lives. In this research we have decided to use primary data on perceptions of citizens as waiting to get the official secondary data might take long and, on that time, we might be deep in these societal problems and it might be late to make new directions on them. Research paper Keywords: Social innovation; Better life index; OECD; Fuzzy TOPSIS; Iran; COVID-19 Reference to this paper should be made as follows: Sharafi Farzad, F., Salamzadeh, Y., Bin Amran, A., & Hafezalkotob, A. (2020). Social Innovation: Towards a Better Life after COVID-19 Crisis: What to Concentrate On, Journal of Entrepreneurship, Business and Economics, 8(1), 89–120

Evaluating innovation capabilities of real estate firms: a combined fuzzy delphi and dematel approach.

Due to strong competition, numerous technology advancements and the monetary policy of the government, the survival of Indian real estate firms now depends on their capacity to measure their existing innovation capabilities, rebuild them and adopt new ones. The aim of this study is to evaluate the technology and human resources innovation capabilities of Indian real estate firms by applying fuzzy Delphi and DEMATEL techniques. After identifying the innovation capabilities through an extensive literature review, a questionnaire is designed based on fuzzy linguistic scales to manage any vagueness of information received. Data has been collected from experts in the field, with capabilities then finalized by using a fuzzy Delphi method. To establish cause-effect relationships among capabilities, a DEMATEL method is applied to the data collected from a second questionnaire. Analysis of the data divides capabilities into two groups i.e. cause and effect. The results show that innovation management, robustness of product and process design capability, strategic planning and knowledge resources fall in the cause group; these are critical findings given the effect on the other capabilities. The study outcomes can help real estate firms to enhance their capabilities with the proposed model providing guidelines and direction in this regard.N/

Social Innovation: Towards a Better Life after COVID-19 Crisis: What to Concentrate On

We know that saving lives of people is the most important issue during COVID-19 crisis, but we should not forget that due to this crisis, the quality of life for many people will change and new social needs will appear and we must be prepared for that. The main purpose of this research is to find out the areas, which are the most affected ones by the pandemic and have a direct impact on citizens’ lives. This research is a quantitative study, which plans to use the opinions of business and management graduates in Iran to present the status of affected fields of better life index by COVID-19 crisis. A fuzzy TOPSIS method is used here to do this ranking. This research has ranked the most affected indicators of better life index by COVID-19 pandemic. In addition, the profile of this impact including the indicators of better life index and their change is also presented in this research. We found out that most affected indicators are Income, jobs, health, life satisfaction and education, respectively. The output of this research can be used for policy makers to start providing support on policies, infrastructures and social innovations on the most affected dimensions in order to reduce the impact of this pandemic on citizens’ everyday life and their quality of life. Also using fuzzy TOPSIS in recognizing the most affected dimensions of quality of life of citizens is a theoretical implication of this research for similar ideas of future researchers. This study is a pioneer in investigating the effects of COVID-19 pandemic on dimensions of life quality of citizens. Also linking the better life index, as a comprehensive index, which has a direct impact on people’s lives to social innovation is another novelty of this research. As it opens a new window for social innovators to know how they can use their innovation capacity to have higher impact on society by shedding light on the main challenges occurred in people’s lives. In this research we have decided to use primary data on perceptions of citizens as waiting to get the official secondary data might take long and, on that time, we might be deep in these societal problems and it might be late to make new directions on them. Research paper Keywords: Social innovation; Better life index; OECD; Fuzzy TOPSIS; Iran; COVID-19 Reference to this paper should be made as follows: Sharafi Farzad, F., Salamzadeh, Y., Bin Amran, A., & Hafezalkotob, A. (2020). Social Innovation: Towards a Better Life after COVID-19 Crisis: What to Concentrate On, Journal of Entrepreneurship, Business and Economics, 8(1), 89–120

Research Article Balancing the Production Line by the Simulation and Statistics Techniques: A Case Study

Abstract: A wide range of the real world problems in industries are related to misbalances of the production line and excessive Work in Process parts (WIP). Simulation is an effective method to recognize these problems with consuming least cost and time. Moreover, total system efficiency of a production line can be extremely improved by examining different solution scenario via the simulation techniques. In this research, we utilize the simulation technique founded upon the software Enterprise Dynamics (ED) for evaluating the cause of these problems and trying to find the improvement solutions in Sadid Pipe and Equipment Company (SPECO). Two parameters of diameter and thickness are important factors affecting the time of workstations. The effects of these factors on process time are evaluated by hypothesis tests. Two improvement scenarios have been presented. In the first scenario, the layout design of the factory has been improved with regard to production process and bottleneck station. In the second one, an essential improvement has been carried out by reduction in wastages. Regarding the accomplished simulations, it is concluded that it is possible to eliminate the existing bottleneck by implementing changes in the locations of production stations or reducing the waste in some stations. The improvements eventually result in balancing the production line

Strategic and Tactical Design of Competing Decentralized Supply Chain Networks with Risk-Averse Participants for Markets with Uncertain Demand

An integrated equilibrium model for tactical decisions in network design is developed. We consider a decentralized supply chain network operating in markets under uncertain demands when there is a rival decentralized chain. The primary assumption is that two chains provide partial substitutable products to the markets, and markets' demands are affected by tactical decisions such as price, service level, and advertising expenditure. Each chain consists of one risk-averse manufacturer and a set of risk-averse retailers. The strategic decisions are frequently taking precedence over tactical ones. Therefore, we first find equilibrium of tactical decisions for each possible scenario of supply chain network. Afterwards, we find optimal distribution network of the new supply chain by the scenario evaluation method. Numerical example, including sensitivity analysis will illustrate how the conservative behaviors of chains' members affect expected demand, profit, and utility of each distribution scenario

A Three-Echelon Multi-Objective Multi-Period Multi-Product Supply Chain Network Design Problem: A Goal Programming Approach

In this paper, a multi-objective multi-period multi-product supply chain network design problem is introduced. This problem is modeled using a multi-objective mixed integer mathematical programming. The objectives are maximizing the total profit of logistics, maximizing service level, and minimizing inconsistency of operations. Several sets of constraints are considered to handle the real situations of three-echelon supply chains. As the optimum value of conflictive objective functions of the proposed model cannot be met concurrently, so a goal programming approach is used. An illustrative numerical example is provided to show the mechanism of proposed model and the solution procedure. In a numerical example, 1 manufacture, 2 warehouses, 2 distribution centers (DCs), and 2 types of final products are considered in a planning horizon consists of 3 time periods. Products are shipped from the manufacturer to warehouses and then are shipped from the two warehouses to two distribution centers. The distribution centers are the point from which the product are shipped to final consumers. The Model is coded using GAMS software on a Core i7 CPU, using 8GB of RAM with MS-Windows 8.0. The optimum design of supply chain, inventory level for warehouses and distributors, and amount of shipments between echelons are determined

Robust approach to DEA technique for supplier selection problem: A case study at Supplying Automotive Parts Company (SAPCO)

Abstract In many industries such as automotive industry, there are a lot of suppliers dealing with the final products manufacturer. With growing numbers of suppliers, the suppliers' efficiency measurement often becomes the most significant concern for manufacturers. Therefore, various performance measurement models such as DEA, AHP, TOPSIS, are developed to support supplier selection decisions. After an exhaustive review of the supplier selection methods, we employ data envelopment analysis (DEA) for computing the relative efficiency of the suppliers and introducing the most efficient supplier as a benchmark. In reality, there are large amounts of uncertainty regarding the suppliers' measurements; therefore, we propose the robust optimization approach to the real application of DEA (RDEA). In this approach, uncertainties about incomes and outcomes of decision making units (DMUs) are involved in the relative suppliers' efficiencies. The proposed RDEA approach is utilized for the selection of suppliers which manufacture the automotive safety components in Supplying Automotive Parts Company (SAPCO), an Iranian leading automotive enterprise. Numerical example will illustrate how our proposed approach can be used in the real supplier selection problem when considerable uncertainty exists regarding the suppliers' input and output dat

Opto-mechanical design for sight windows under high loads

In this study, the design aspects of optically accessible pressure vessels are investigated via a case study of a High Pressure Combustor experimental rig. The rig was designed to take optical measurements of combustion, simulating the conditions found in internal combustion engines and turbines. Although, it is not new to equip chambers and reactors with sight windows, important aspects of design and relevant information regarding optical access is missing or are insufficiently explored or not readily accessible in the existing literature. A comprehensive review of requirements for optical access to such high-pressure, high-temperature systems has been conducted. It is shown in a readily-navigable format as function of application and precision, with data and technical correlations hitherto not found in a ‘user-friendly’ style. The material selection procedure is detailed and supported by a complete comparison of optical materials and relevant properties. The review revealed a significant inconsistency in mechanical properties claimed in the literature for optical materials. As a response to this, increased safety factor values are suggested as function of level of uncertainties and effects of failure, typically three to four times higher than the industrial standard. Moreover, newly developed equations are presented linking performance analysis to the design criteria