Comparative Evaluation of Supply Chain Management Strategies: A Simulation Approach

Supply chain management has become one of the most important sources of competitive advantage in different industries. For years, researchers have investigated the various processes within supply chain. There has been an increasing attention placed on performance, design and analysis of supply chain. However, the supply chain is a complex model so it is difficult to analyze the performance of a supply chain philosophically. To evaluate the control mechanism for a supply chain, simulation is one of the effective methods. There are five common supply chain models built up in this paper. From the simulation results, various performance measures such as transportation cost, resources utilization, inventory level, and order cycle time can be calculated.published_or_final_versio

A coordination framework for distributed supply chains

Supply chain is a network of cooperating organizations that are involved through upstream and downstream linkages. Such a complex system cannot be modeled simply by mathematical equations without simplification of the problem. Recently, Multi-Agent System (MAS) is proposed as a modeling technique to represent supply chain networks. In fact, many application problems in MASs that are concerned with finding a consistent combination of agent actions can be formalized as Distributed Constraints Satisfaction Problem (DCSP). The main purpose of this paper is to propose a novel coordination framework by adopting the DCSP philosophy for distributed supply chains, which are modeled by MASs, subjected to uncertainties. Simulation results indicate that the proposed mechanism outperforms traditional stochastic modeling in solving supply chain dynamics in terms of total cost and fill rate of the system. © 2004 IEEE.published_or_final_versio

An introduction of dominant genes in genetic algorithm for scheduling of FMS

This paper proposed a new idea named Dominant Genes (DGs) in Genetic Algoriths (GAs) to deal with FMS scheduling problem with alternative production routing. In traditional GAs approach, the crossover mechanism will randomly select a number of genes to undergo crossover. However, these selected genes may not contain or contain only part of the critical structure of its original chromosome. In addition, since the inherited complexity of the scheduling nature, the changes in the structure of the selected genes will further influence its strength. To tackle this problem, the proposed DGs in this paper are to identify and record the best genes in the chromosome. A new crossover mechanism is also designed to ensure the best genes will undergo crossover, and retain the originality of the structure of the crossover genes. The performance of the proposed DGs is testified by comparing it with other heuristic optimizations. The shows that DGs perform better than other approaches. ©2005 IEEE.published_or_final_versio

Optimization of machine flexibility in an ion plating cell

In 1970s, manufacturing system performance was heavily depended on productivity. Manufacturers only concentrated on increasing productivity by increasing the number of workforce. The concept of flexibility began to introduce into the industry since 1990s, manufacturers realized that flexibility was a better solution to improve productivity by responding the changing environment in manufacturing system. However, limited researches on machine flexibility in Ion Plating (IP) industry were studied, most of them have focused on product development and quality of coating. The aim of this paper is to determine the optimal level of machine flexibility in an Ion Plating Cell (IPC) to improve the entire system performance. A Machine Loading Sequencing (MLS) model based on multi-objectives Genetic Algorithms (GA) was developed. In the case study, industrial data of a precious metal finishing company has been input into the proposed Machine Loading Sequencing Genetic Algorithm (MLSGA) model. Different level of machine flexibility will be assigned into different machines to determine the optimum while the overall system performance (i.e. on-time delivery, quality of product and production cost) has been maximized. The results demonstrated that the machine flexibility level in IPC should be zero under the recent IP technology. However, when the quality of coating is improved, machine flexibility should be introduced. © 2004 IEEE.published_or_final_versio

Macro-approach of cell formation problem with consideration of machining sequence

Cellular Manufacturing System (CMS) which is based on the concept of Group Technology (GT) has been recognized as an efficient and effective way to improve the productivity in the factory. In recent years, there has been much effort done for continuing to improve CMS. Most researches concentrated on distinguishing the part families and machine cells either simultaneously or individually by considering of minimizing intercellular and intracellular part movements. However, fewer researches have studied the impact of the sequencing of machine cells. In light of this, the main aim of this present work is to study the impact of the sequencing of allocating the machine cells in minimizing intercellular part movement. The problem scope, which is also called as machine-part grouping problem (MPGP) together with the background of cell layout problem (CLP), has been identified. A mathematical model is formulated and part incidence matrix with operational sequence is often used. Since MPGP has been proved as an NP complete, genetic algorithm (GA) is employed as cell formation algorithms in solving this problem. © 2004 IEEE.published_or_final_versio

A random search approach to the machine loading problem of an FMS

This paper discusses a modelling framework that addresses operational planning, problems of flexible manufacturing systems (FMSs). A generic 0-1 mixed integer programming formulation integrating the part selection and loading problems has been proposed. The constraints considered in the problems are mainly the availability of tool slots and machining time on the machining centres. The above problem is solved using an algorithm based on Simulated Annealing (SA). The potential capability of the approach is demonstrated via a small set of test problems. ©2004 IEEE.published_or_final_versio

Outage planning of electrical power system networks using genetic algorithm

An electrical company is responsible for the maintenance of a transmission network of high voltage electricity. The maintenance schedule must be planned so as to minimize outage costs, taking into consideration various factors such as system security/reliability, system availability, and manpower utilization. With the rapid growth of organization, planning engineers are required to fulfill additional roles in order to increase productivity. To this end, a fast response and accurate mechanism is required to assist the planning engineers in dealing with the daily operation. This paper describes how a proposed maintenance schedule can be obtained automatically by the adoption of genetic algorithm. The main aim is to determine the maintenance schedule of circuit outage with minimizing the maintenance cost and maximizing the circuit availability under certain unavoidable system constraints. Further, an additional search mechanism called "final tuning search" is developed to enhance the system performance.published_or_final_versio

Information integration platform for CIMS

A new information integration platform for computer integrated manufacturing system (CIMS) is presented, which is based on agent and CORBA. CORBA enhances the system integration because it is an industry-standard for interoperable, distributed objects across heterogeneous hardware and software platform. Agent technology is used to improve intelligence of the integration system. In order to implement the information integration platform, we use a network integration server to integrate the network, design a generic database agent to integrate database, adopt multi-agent based architecture to integrate application, and utilize wrapper as a CORBA object to integrate legacy code.published_or_final_versio

Design and development of a flexible workflow supply chain system

This paper attempts to suggest a methodology for the design and development of a flexible workflow supply chain (FWSC) system for achieving flexibility to cope with unexpected changes. In particular, a multi-agent approach, which provides the capability to meet the requirement of a FWSC system, is proposed. Such a system is characterized by its capability to cope with the increasing complexity setting of organizations and markets, providing effective information exchange between business partners. The methodology for the design and development of a workflow agent is also covered in this paper. This paper is concerned with the suggestion of a multi-agent methodology, which is able to enhance the effectiveness in terms of the information flow in a supply chain, thereby providing more alternatives and ideas for those researchers who are interested in this field of study.published_or_final_versio

Object-oriented architecture of control system for agile manufacturing cells

The depiction of the agile manufacturing cell includes a synopsis of some of the change proficiencies obtained by the configuration. To achieve agile configuration, the cell control system for agile manufacturing must be rapidly and efficiently generated or modified. In this paper, the object-oriented architecture is defined that supports design and implementation of highly reconfigurable control systems for agile manufacturing cells, which is composed of database objects, control objects, and resource objects, so as to reduce costs and increase a control system's agility with respect to changing environmentpublished_or_final_versio