Sharif Digital Repository

This research deals with the problem of dynamic pricing of perishable assets. In this problem there are two sources of randomness: the arrival rate of customers and their reservation prices. In most studies considering this problem, it’s assumed that process of arrivals of customers follows a Poisson process with a given intensity. Thus this process is assumed to have independent increments and the information regarding the arrival times of previous customers doesn’t have any influence on the distribution of arrival times of future customers. In some recent studies it’s assumed that customers’ arrivals follow a conditional Poisson process with an unknown intensity. The distribution of this... 

Dealing with uncertainty in demand, Seasonal product retailers have to make two important decisions. The first one is pricing of the products during their selling season and the second issue is the inventory level and also reordering decisions during the aforementioned period. It is worth mentioning that all products are using a shared capacity which left us barehanded with the pricing and optimizing inventory levels independently. In this thesis, a new model for retailers is presented which includes demand learning and determines optimal prices and inventory policies for multiproduct industries  

In this research , we consider a two-echelon system including one supplier , one vendor and some buyers. Every buyer has a distinct and uniform demand . The policy for ordering is (r,q) and shortage is not permitted. Buyers have no dependence on each other and every buyer orders it's demand from the vendor by itself . Hence, the vendor will be faced with discrete and different demands. Considering these assumptions, we use vendor management inventory and determine the order quantities for buyers and vendor in order to minimize the total cost of system  

Key conservation organizations to meet customer needs and attitudes of SCM is not only the ultimate goal of customer relationship that the final product delivers, but a sequence of suppliers in this work considers the integration of organizations involved in the synchronization process material, and financial information to improve the competitiveness of the supply chain are examined. The proper functioning of the supply chain , a key role in achieving sustainable success of an organization and its profitability goals, especially. In this regard, the establishment of a system of supply chain performance measurement in continuous improvement of its performance is recommended. In each of the... 

This thesis presents an inventory control system which is based on Meta-heuristic Algorithms.In this thesis we will optimize the input values of our tree-echelon inventory model (keeping costs,stock worth,reorder costs,...) with these Algorithms. The presented method is able to determine the optimal stock level, costs of system and number of shipments in the system. The method is basically a decision support system (DES) and it is able to provide the order scheduling parameters of goods at operational level. The aim of the current research is to demonstrate that a Meta-heuristic algorithmis capable of solving complex inventory problems and with future improvements it is able to achieve... 

Supply chain management involves making integrated decisions by suppliers of primary materials during supply chain until consuming the product by final costumers. This procedure is made up of three main decisions: supply selection, production, and distribution. Selecting supplier is an important issue in making decisions, which consist of qualitative and quantitative factors to determine the suppliers with highest potential to provide company requirements with an acceptable cost. In this study, a retailer is considered in contact with some suppliers. The retailer is willing to purchase some goods form high potential suppliers. Each supplier has a fixed delivery time which differs from... 

In this thesis, we consider various Make-to-Order systems as a version of integrated production-inventory systems. Most Make-to-order systems can be sufficiently modeled by a queueing system with inventory in which completing each service in the queueing system requires an on-hand inventory. Unlike most researches in this field, we present an analytical approach. In all systems we embed a stochastic process with joint state space that can entirely describe the state of system. Then steady state distributions are derived. Those distributions are applied to compute performance measures and long-run average cost function which can be used for optimization. In our Make-to-Order models, demands... 

Given the increased competition in supply chains and enlargement of their scale along with increasingly significant role of distribution systems, design and optimization of novel systems with comprehensive approaches in a timely manner has become important more than ever. One of such modern, efficient systems is cross docking in which the distribution network is omitted and thus operations are carried out faster and the productivity is increased. In this system, processes like packaging is done in cross docking and the goods and products are directly sent to customers. This study investigates a long-term and a short-term approach to the design of in two distinct problems. In the first... 

Power distribution network planning and related optimization is an interesting research subject and many papers have been published on this topic. Distribution network planning started in developed countries. Therefore network models are based on reliable network data, educated crew and low interest rate. Nowadays, Iranian engineers and researches try to use their research result for solving network optimization problems but sometimes the result of optimization is not achievable in reality. In current thesis, modeling approaches developed by previous researchers were compared and the effect of model simplification was evaluated. This evaluation was based on data gathered from local power... 

The subject of this thesis is a two-echelon inventory system with a manufacturer and multiple distribution centers (DCs) that satisfy the demand originating from multiple sources. Demand from each source follows an independent Poisson process. The transportation times between the manufacturer and the DCs are assumed to be positive which may require keeping inventory at both the warehouse and the DCs. Inventory in both echelons is managed using the base-stock policy. The manufacturer works with
M/M/c product system. The cost of demand fulfillment for each DC consists of inventory holding and backlog costs. The objective is to determine the optimal base-stock levels at the DC  

In this research, we study the differences between the centralized and decentralized approaches in a two-stage serial supply chain including a manufacturer and a retailer under the lost sale policy. The centralized approach results in optimal solution of the system and the decentralized one is based on Stackelberg game in which the manufacturer is the leader. The retailer uses the continuous review (r, Q) policy and the demand arrives according to the stationary Poisson process. In order to obtain the solution for two approaches, a set of computational steps are developed. Furthermore, we provide a numerical example and the corresponding sensitivity analysis to compare the two approaches.... 

Project is defined as all activities with a definite beginning (start) and end (finish) aiming to achieve a defined target through defined resources. Literature reviews in the field of project management have shown the importance of project management capabilities for evaluation and optimization. There are many factors in project management which can lonely disrupt the timing and progress of the project. One of the most important factors that in effective and unfortunately has been less measured due to its intangible characteristic in the project is known to be the "human factor". This factor is involved from the first day a project starts and will continue till the end of the project.... 

In real production systems, the process is always bound with the production of faulty items which different approaches may be taken toward handling these low quality items according to the nature of the industry and product. Repairing, discarding or selling items in a secondary market are some of the possible actions. We investigated the essentiality of coordinated decision making between a supplier and a buyer in this environment hence developing a model to minimize total costs of two parties with an attitude towards improving quality of production system. In common two layered supply chains, the buyer defines the economic order quantity (EOQ) according to its own decision criteria. These... 

Recently, reducing greenhouse gas emissions and the damage to the environment is very important. Due to the increasing environmental awareness of the people on the one hand, and government pressure to reduce damage to the environment on the other hand, has led organizations to pay more attention to this important issue. In addition, these organizations in order to participate in the global competition, should consider green criteria along with other criteria. Hence, the organizations to outsourcing part of their work are looking for Suppliers who along with other criteria also meet the criteria for being green. In this study, a new two-stage approach based on fuzzy... 

In this study, I examined a two-level supply chain with two-way information exchange in which both the manufacturer and the retailer will be informed of each other’s stock.In order to make use of this type of information exchange, the manufacturer and the retaile modify their single-level base-stock policy to a two-level, state-dependent base-stock policy.Later, I exerted the lost sale policy. And finally, I investigated the impact of this type of information exchange on the general chain criteria. Then, I point out the advantages of this method.
Applying the mentioned method reduces the total cost of system as well as decreasing the average amount of manufacturer’s inventory along with... 

In this research, effect process TOC in MRP system have been studied,therefore, first the hypothesis in TOC process and MRP system have been studied and generated. Afterward, whit the use of library and sydies the research guestions have been compiled. The society under studyis an aluminium oasts manufacturing daycust tabriz company. For surveying the memtioned company, samed documents hase been studied. After gathering all information and documents, and analyzing them, the result has been revealed. Therefore the effect of TOC and MRP process an production system has been comeout. At present situation, the mast crucial factors for suruival and compdtetion are ones couse the reduction of the... 

It has been passed more than half a century from the application of value methodology (including value analysis, value engineering, value management and value planning) to improve the project value and so far, thousands of value studies (VSs) have been performed all over the world. Because of the nature of this method, in all of data value studies, new approaches and valuable knowledge – which is called “study outcomes (OS)” in this study – are produced by specialists. However, nearly all of the new VSs as well as planning, designing or performing of new project is performed regardless of previous VS repeatable outcomes whereas presence of some previous VS members can be useful to enhance... 

In today’s competitive world, using an efficient forecast method is necessity for companies. To now, many forecast methods have been developed, but many of them have not an expected efficiency. In this research, we develop a new hybrid forecast method with application of forecasting retails demand. The hybrid method is the combination of ARIMA method and neural networks. To test the efficiency of the method we use the 96 weeks data of plastic containers demand. We also comprise the hybrid method with other forecast methods including naïve method, ARIMA method and neural network method by applying root mean square error and mean absolute percentage error indexes. In the case of plastic... 

Planning orders and inventory is one of the most important issues in the planning of petrochemical production. Considering the customization of this industry, orders planning includes a large part of it. Also, in order to reduce the great cost of inventory storage, planning to reduce inventory must be considered. In this regard, we intend to present a model with simultaneous consideration of orders and inventory planning in this research, the ability to decide on acceptance of orders and determine the level of production of products in conditions of uncertainty of demand with random trapezoidal demand in each period can be assumed. This model will practically play a key role in improving... 

Nowadays competition in business world has increased drastically. Under these competitive circumstances, it is the supply chains that compete against each other rather than individual firms. Accordingly trying to achieve integrated and synchronized management of activities within a supply chain has become inevitable. Recently researchers have found interest in a particular problem in a supply chain and that is to minimize inventory and routing costs in a supply chain. This problem is known as Inventory Routing Problem (IRP) and has been intensely examined in past few years. In this thesis we will try to expand this well-known problem in pricing dimension. We call this new problem “Inventory...