Seyed Mohammad Taghi Fatemi Ghomi; Ehsan Arabzadeh; Behrooz Karimi
Abstract
Home health care services have a key importance in modern societies. Most organizations working in this area in Iran use the traditional procedure to plan and manage medical staff and determine the arrangement of visiting patients. This procedure often increases costs and reduces the satisfaction of ...
Read More
Home health care services have a key importance in modern societies. Most organizations working in this area in Iran use the traditional procedure to plan and manage medical staff and determine the arrangement of visiting patients. This procedure often increases costs and reduces the satisfaction of patients. In this paper, a multi-period routing and scheduling model is proposed in order to visit patients and provide them medical services. Considering both dependency and independence of a patient's visits with each other, assuming the model as multi-depot as well as multi period are some innovations of this study. The main purpose of the proposed model is to reduce total costs of home health care organization. Model has been solved in small scale by GAMS software. To solve the model in large scale, developed Variable neighborhood search is proposed and compared with simulated annealing algorithm and ant colony system. Results show that costs are decreased and the proposed algorithm has better performance
Milad Yari; Mir Saman Pishvaee; Armin Jabbarzadeh
Abstract
The main aim of this paper is to provide a model for supply chain design of decorative stones in competitive conditions by taking into account the risk of the disruption. The main tools used in this study are mathematical programming and game theory which Stackelberg game is often used for competitive ...
Read More
The main aim of this paper is to provide a model for supply chain design of decorative stones in competitive conditions by taking into account the risk of the disruption. The main tools used in this study are mathematical programming and game theory which Stackelberg game is often used for competitive modeling. The aim of the proposed model is to consider potential risks of disruption and competitive situation in the market. Also, due to the problem situation, we use meta-heuristic methods like particle swarm optimization and biogeography based optimization for solving and verification of the model. The results show that the occurrence of disruption affects in location decisions of production and distribution centers, price of products and profit of chain components
Mohammad Hossein Tahmasebi; Kaveh Khalili Damghani; Vahidreza Ghezavati
Abstract
One of the most important problems facing distribution companies is to find the best locations for depots and also proper routes for transportation vehicles in order to optimize their supply network. This study aims to examine the problem of location-routing for post offices in Tehran. To achieve this, ...
Read More
One of the most important problems facing distribution companies is to find the best locations for depots and also proper routes for transportation vehicles in order to optimize their supply network. This study aims to examine the problem of location-routing for post offices in Tehran. To achieve this, a bi-objective location-routing problem is proposed. In order to make the problem more realistic, time constraints are taken into account. A suitable solution procedure on the basis of customized goal programming is developed to solve the proposed model. The proposed model and solution procedure are applied in post offices in Tehran, Iran. The results of proposed model show considerable savings in time and cost of planning in comparison with the current planning in the case. The proposed model can be applied in other cases such as location of garbage bins in city and routing of collecting vehicles. Other significant parameters in urban planning can be considered as uncertainty in this model in the future research. This model can be customized for whole of Iran and therefore, meta-heuristic methods can be used to solve the instances in large scale
Majid Hooshmandi Maher; Maghsoud Amiri
Abstract
In most industries the cost of raw materials and product components constitutes almost 60% percent of a product cost (in some industries up to 80%). In this condition، proper sourcing can play a key role in an organization's efficiency and effectiveness، because it has a direct effect on cost reduction، ...
Read More
In most industries the cost of raw materials and product components constitutes almost 60% percent of a product cost (in some industries up to 80%). In this condition، proper sourcing can play a key role in an organization's efficiency and effectiveness، because it has a direct effect on cost reduction، profitability and flexibility of a company. In this paper، to determine the optimal order quantity, multi supplier،multi product and during several periods، shortage and surplus،incremental discounts، multi objective and multi criteria nature of the problem، uncertainty in demand، lead time، fixed order cost، supplier quality level and every period budget are being considered. To incorporate the effective criteria in mathematical model، analytic network process approach has been used. After developing the robust multi objective mixed integer programming، a numerical example is presented. Finally, the results and suggestions for future studies are presented
Abolfazl Kazemi; Vahid Hajipour
Abstract
In today's competitive markets quality as a competitive advantage is important, but quality always comes with price, so cost of quality recognition and proper division has always attracted attention of many researchers in the literature. The related literature show that from the time quality costing ...
Read More
In today's competitive markets quality as a competitive advantage is important, but quality always comes with price, so cost of quality recognition and proper division has always attracted attention of many researchers in the literature. The related literature show that from the time quality costing is introduced, all attentions were to identify the different costs of quality and sometimes there were different views to these costs which have similarities in the principle of classifications. Despite to successful reports provided for implementing these methods in identifying costs of quality, it can be seen a gap in improvement processes. Although the identification of costs and improvement projects in this field, often improve the level of products and service quality and ultimately lead to increased customer satisfaction, But certainly there is a significant difference between non-optimum and optimum resource allocation in receiving results. The aim of this study is to design an approach that reach to a certain quality level in a consistent and cost less way. In this approach, after identifying the types of quality costs, difference in importance of costs is determined. The first weight comes from financial results obtained from costs identification, indeed it is the proportion of the financial load of each cost to total quality costs. Stakeholder opinion based on BSC in second weight calculating process comes into AHP as expert group.
Seyedeh Farnaz Kouhbanani Nejad; Darush farid; Hojatallah sadeghi
Abstract
Modifications are an integrated part of economic evolution in financial section which include reforming the capital market structure, innovating in tools and an environment with more comprehensive discipline. Two dominant schools of thought in the literature on stock markets are fundamental and technical ...
Read More
Modifications are an integrated part of economic evolution in financial section which include reforming the capital market structure, innovating in tools and an environment with more comprehensive discipline. Two dominant schools of thought in the literature on stock markets are fundamental and technical analysis. Selection the portfolio would be so important. So we use both fundamental and technical analysis to evaluate companies' stock and then in order to form a portfolio which consider different risk states and investor’s preferences utilize Mamdani Fuzzy and mixed integer linear programming model. The reasons for the use Mamdani Fuzzy system are its capability of working in vague environment and using human knowledge and for mixed integer linear programming model is its capability in finding the optimum solution among the several available ones. The results of evaluating the performance of formed portfolio for three cases of Risk averse, Risk neutral and Risk prone investor show that the performance of proposed portfolio is positive and proper, but in a more accurate scale the formed portfolio has a more proper condition for the risk averse investor.
Alireza Alinezhad
Abstract
In the last decade, despite the extra importance of service and its increasing development in global and national economies, it has received less attention in comparison with manufacturing industries. The evaluation of performance in service organizations has always been one of the main challenges in ...
Read More
In the last decade, despite the extra importance of service and its increasing development in global and national economies, it has received less attention in comparison with manufacturing industries. The evaluation of performance in service organizations has always been one of the main challenges in this area. Parasuraman and colleagues’ five dimensional model is one of the most common models to evaluate the quality of service and was used in this paper to evaluate the service quality in CNG stations in Zanjan Province. In this paper, the Data Envelopment Analysis (DEA) was also used to assess the relative service quality in 36 CNG stations in Zanjan province. Due to the high importance of service quality, it was considered as the functional output of CNG Refueling Stations. The number of employees, number of dispensers, fixed monthly cost, and monthly allocated credit to stations were considered as functional inputs of CNG stations. After obtaining the station’s rank, finally, the sensitivity of results was analyzed using the proposed method of Jahanshahlu and colleagues. Also, the results showed that the developed model of multi criteria data envelopment analysis has better performance than basic models.
