Sharif Digital Repository

Kanban inventory system has been applied as a tool of implementing lean production and just in time philosophy since three decades ago. By implementing kanban in supply chain which consist of suppliers , producers , distributors and consumers, real information of demands transfers upstream and materials flows downstream and integrated supply chain can be optained. Therefore a lot of mathematical models for optimizing kanban inventory system in supply chain has been developed to implement just in time philosophy and reduce total inventory cost in supply chain systems this research consist of two main section. In the first section , kanban and supply chain primary concepts are reviewed and... 

Mixed-model production Lines manufacture or assemble more than one product with similar production characteristics or different models of a product on the same line. This level of flexibility in commodities is very important to face diverse customers' expectations. In this article, U-shaped, mixed-model, synchronous lines with stochastic task times are discussed in a cost-oriented perspective. In U-shaped, mixed-model, Simultaneous consideration of line balancing and model sequencing is essential because different models require different tasks with different task times and the sequence of models determine the models which is produced in each station in each cycle. This sequence affects the... 

The rapid growth of e-commerce and home delivery has increased the number of vehicles on the streets. As a result of that, traffic congestion and, in return, air pollution have got worse. To prevent this trend, using electric vehicles is highly suggested, and in recent years, some companies have started using autonomous delivery robots. Since these robots can travel for a limited time, it is better to use them in conjunction with other vehicles, like vans. In this research, we propose a mixed-integer programming model to formulate a two-echelon time-dependent vehicle routing problem with simultaneous pick-up and delivery. In the first echelon, vans travel from a central depot to parking and... 

Distribution of goods by vehicle routing with split delivery and effective usage of trucks are two important problems which are useful separately and could be applied for different kinds of depots with different trucks to satisfy customers’ demand. Combination of these two NP-hard problems can play a great role to decrease transportation cost. Complexity of this problem is so much that we cannot solve big-size problems by exact methods or branch and bound method in limited time. We introduce metaheuristics methods such as Tabu Search, Simulated Annealing and Ant Colony Optimization which have been presented before, concisely. We present various constraints in routing and distribution,... 

In this research, we propose a formulated approach to locate and allocate two level of a three-level closed-loop supply chain consist of a number of capable points production facilities, redistribution centers and customer clusters for multiple products in multiple time periods. Also, we consider environmental aspects in this supply chain network by taking into account an objective function, aside from cost objective function, in the template of emitted carbon dioxide. In this research for the first time we consider vehicles’ emitted CO2 different in each period which is a result of gradual depreciation of vehicles. In the end for the sake of validating model’s performance we developed few... 

Environmental problems and the consequent governmental regulations, has led supply chains into reverse and closed-loop supply chains. Application of problems such as "Vehicle Routing Problem” has diminished in the closed-loop supply chain, and instead of them, the problem of "Vehicle Routing Problem with Deliveries and Pickups" has become more important. On the other hand, tendency of supply chains to running information in the chain in a desired way, has led to grow the attention to establishing policies of “Vendor Managed Inventory". It seems that by tending the supply chains to closed-loop supply chains which are utilizing the policy of "Vendor Managed Inventory", application of problems... 

Managing the supply chain is a competitive necessity in today's global marketplace where differentiation between products and services means providing a total value package that can compete for an increasingly discerning and empowered customer. Today's view is one of integration. Supply chain management is the integrated management of business links, of information flows and of people. This research is based on a study conducted to introduce a reference model for Supply Chain integration. In that study, 10 drivers are introduced as keys for integrity in Supply Chain. The objective of this article is to discuss a method which has been developed to measure objectively and quantify the level of... 

In the intricate realm of supply chains, the ripple effect, akin to an abrupt storm, can jeopardize the stability and efficiency of the entire chain. This research aims to identify and prioritize the causative factors of this disruptive phenomenon, employing the Fuzzy Delphi Method. The Fuzzy Delphi Method is utilized in this investigation, as it possesses the capability of integrating expert knowledge with quantitative analyses. To construct the questionnaire, the results of previous studies were initially examined, and the influencing factors were identified. Subsequently, drawing upon the knowledge and experience of ten prominent experts from the "NAVABEHDASH" Organization (PANBERES), the... 

In recent years, Supply Chain Management has become one of the most desired concepts for Industrial engineers. In this thesis, specifically, one of the SCM’s aspects, Joint Economic Lot Sizing1, which in literature have been studied by various people with different viewpoints, is considered and a two-stage supply chain facing certain demands is studied. These demands are changing as a function of selling price determined by a supply chain and the goal is to increase the chain’s total profit in comparison of individual policies in which members decide about their profits separately. The optimal amount of selling price varies end-customer demands exponentially and leads to changes in economic... 

Nowadays the issue of recognizing customer’s needs and leading different activities of industrial units to obviate such needs are important concerns and are coined as “Customer Relationship Management” in business literature. What’ s more, with the development of information technology ,creating the possibility to gather, warehouse and analyze huge amount of data quickly, “Data Mining” subject is presented to analysts and experts as a powerful tool. Currently in many aspects of CRM, analysts are considering Data Mining techniques in order to identify customers’ behavior pattern, performance and predict customers’ behavior and to specify their desires based on this pattern. This Thesis is to... 

Inventory problems are studied for a long time and many authors have investigated models with shortage phenomenon. To reduce inventory holding cost or decaying items we can have a shortage period in witch a part of demand is backordered; Although we pay fines to pending costumers, as shortage period is extended a larger portion of them will refuse to wait until replenishment. So, calculating an optimal duration for on hand inventory and shortage period with respect to inventory costs has became an interesting research field. However, related studies are rarely appeared in supply chain researches, where an integrated inventory model for a supplier and a retailer is proposed; especially when a... 

Locating wireless transmitters is one of the most important issues. That’s why many researchers have worked in this subject recently. Communication Engineers always want to optimize the productivity of wireless transmitters. They prefer to cover a region completely by minimum cost, so they use analytical tools for solving this kind of problems. This type of optimization is very useful for cellular Networks. There is a different kind of wireless services such as high-speed Internet services; their goal is maximizing the covered demand points by minimum cost not covering all of them. Experts use maximal covering location problem for modeling this kind of problems. At first, an extension of one... 

In decentralized Supply Chains, each member decides based on his own interests. Conflict of interests results in suboptimal decisions and poor performance for entire supply chains, as well seriously harms credibly information sharing across them. In this thesis, coordination of decisions in supply chains in the context of Capacity Procurement problem are studied in different situations in form of three models. In first model, a dyadic supply chain with stochastic demand and exogenous price is investigated by taking various costs into account. PARD and RCRS contracts are designed and proposed in order for coordination of decisions respectively in full and partial information updating... 

Today, using Radio Frequency Identification (RFID) technology is of a remarkable interest to the industry and services sectors. Application of this technology could result in higher levels of productivity and effectiveness. On the other hand, department stores are increasing in number and size in the country. Application of RFID technology could play an undeniable role in both reducing the time each customer must spend in order to complete their purchase, and accelerating the logistics operations of these stores.
Through literature review, this research studies application of RFID technology instead of other identification technologies such as Bar-Code, reveals strengths and weaknesses... 

Refer to increasing importance of logistic and influences of it on economy improvements and increasing the number of third party logistic users in all around the world and also lack of such companies in Iran, this thesis is going to discuss about feasibility study for using TPLs in automotive industry. After study and review on literature and statements of the subject and representing features of TPLs compared with other logistic companies and identifying important logistic companies, this thesis is going to identify local and over the seas companies and study them, study current rules and regulations in country and present legal defects for TPL companies. Finally it represent the technical... 

The hub networks are applied for commodity flows in the systems, among whose nodes the direct connections are both impossible and expensive. The dependency and interaction of demands are dealt with in this thesis. The dependency of demands are the results of some significant aspects, the most important of which are selecting or not selecting a node as a station, allocating or not allocating a demand to a hub, and associating with a path, to name but a few. Then, the ideas of hub location problem, interaction model, and eventually commodity transportation have been considered together.
In this master thesis, a model having a quadratic and non-linear objective function has been developed.... 

Cross-docking is an innovative logistic strategy which brings significant advantages in-cluding little or no inventory in the warehouse. In this concept, coordination between in-bound and outbound trucks is quite important. This research studies the scheduling prob-lem of inbound and outbound trucks considering a cross-dock system with multiple receiv-ing and shipping dock doors. Moreover, due to justifiability of all trucks to carry multiple product types, product assignment from inbound trucks to outbound trucks is determined simultaneous to scheduling. As an exact solution approach a MIP model is presented and since the problem is shown to be NP-hard, it can only be used to solve small... 

This thesis studies a multi-product location-routing-inventory problem in which location-allocation, inventory and routing decisions are to be taken in a three-level supply chain including suppliers, depots and customers. Each product for each depot could be supplied by more than one supplier and each supplier has a limited supplying capacity per period. Products are distributed from depots to customers by a homogeneous fleet of vehicles. Backlogging is allowable for each customer on the condition of not exceeding a fraction of customer’s demand. A mixed-integer programming formulation is presented to describe the problem then a new hybrid heuristic algorithm based on the simulated annealing... 

This paper studies a multi-product, multi-period location- routing- inventory problem in a three-level supply chain including suppliers, cross-docks and customers. Each cross-dock could be supplied by more than one supplier and each customer could be supplied by more than one cross-dock. In the first phase we find the best locations for the cross-dock and allocate them to customers and suppliers by considering inventory costs. . Then, in the second phase Products are distributed from cross-docks towards customers using Heterogeneous vehicles. In this article the option for split delivery is enabled and furthermore, backlogging is allowable for each customer. The model presented in this... 

Logistics includes the flow of goods, information and other sources between production and consumption node to meet the demand of customers. Basically, Logistics includes the integration of information, transportation and inventory. This study is in association with how to phase-out the old product when the new one is developed, and also is about how to manage the remaining inventory in a phase-out period focusing on such decisions as time and discount amount. Often in retailing system, old products have been phased out with an introduction of a new one by distributors. In order to sell this amount of products in a specific time period retailers need to create a mechanisim to phase-out the...