طراحی یکپارچه سازی مدیریت جریان مواد در محیط تولید کسب و کار الکترونیکی

A material flow management (MFM) system that controls and manages material flows on the shop floor is a key component of enterprise information systems. It typically runs as a centralized software application, which becomes difficult in providing desirable system performance, robustness, flexibility, and interoperability in an e-business manufacturing environment. This paper proposes a solution to the design and development of a scalable, reconfigurable, and distributed MFM system. Using the concept of Virtual Production Lines, production lines can be logically configured, and operated, respectively, in processing different families of products; MFM modules/instances are accordingly created to control and manage material flows in corresponding production lines. By reducing the complexity of MFM through the use of decomposed MFM instances and taking advantage of family-type process configurations, a manufacturing system can cut down machine setup time, reduce production cycle time, and improve system responsiveness. Moreover, multi-agents are utilized in the decomposed MFM instances that directly interact with enterprise workflow systems, so information on material consumption and movement can be delivered to office-level planning systems in a timely manner.

In an e-business manufacturing environment, it is essential for the completeness of both “e” and “business”. For instance, customer orders are taken over the Internet and the products are made and delivered as promised. Correspondingly, information systems in a manufacturing enterprise can be classified as a business- or office-level system and plant-level system. The office-level systems normally include office-level planning, scheduling, sales, supply chain, and logistics management applications, while the plant-level systems would include applications directly tied with value-adding manufacturing operations and activities, such as engineering, manufacturing execution, and shop floor controls. As manufacturing business environments are confounded with rapid changes in business operations and customer demands, integrated information systems across different business unit domains become vital for manufacturing enterprise to ensure informed decisions made operationally, tactically, and strategically. However, due to the lack of sufficient investigation and investment in enterprise integration, office-level systems usually do not have effective connectivity to shop floor equipment. As a result, implementation of enterprise integration is usually costly and painstaking; the majority of enterprises cannot afford to conduct enterprise-wide system integration [8]. How could the executives of a manufacturing enterprise make informed business decisions when the office-planning systems have no real-time and accurate data on the status of inventory availability, equipment utilization, and production schedules [2], [7] and [18]? Manufacturing execution systems (MES) have been researched and developed to bridge the shop floor and office-level planning systems [3], [20] and [25]. On the one hand, MES take in pertinent data from office-level planning systems and ensure that their information is acted on intelligently on the shop floor; on the other hand, MES consolidate shop floor data and transform them into business information, focusing on the delivery of accurate production status to office-level planning systems in a timely manner [21]. Material flow management (MFM) is an essential component and plays a critical role in MES [18]. This paper proposes a solution to the design and development of a scalable, reconfigurable, and distributed MFM system. Using autonomous software agents enables the direct communication between office-planning systems (e.g., supply chain management) and shop floor MFM systems. Material consumption data can therefore be directly delivered to users including both internal employees and supplier's correspondents. In a great detail, this paper discusses how an MFM system governs material movement from equipment to equipment on the shop floor. By incorporating the concept of virtual production lines in production control, an MFM system can be developed as a distributed system through decomposition and coordination, resulting in improved performance, robustness, flexibility, and interoperability for the overall shop floor information systems. The remainder of the paper is organized as follows. Section 2 briefly reviews a typical design of MFM and proposes a distributed MFM architecture based on virtual production lines. Section 3 discusses how a collection of distributed computing MFM instances can be decomposed and synchronized. Section 4 presents the method of synchronizing MFM activities between suppliers and the shop floor using multi-agent technologies. Section 5 describes an implementation of the proposed distributed MFM solution. Finally, Section 6 provides conclusions for this research and highlights the future research venue.

This article discussed a methodology for the integration design of a distributed MFM application on the shop floor. The concept of VPL was applied for the development of distributed, modularized, and decomposed MFM instances. First, a complex shop floor can be divided into different virtual production lines to manufacture different kinds of family products, so MFM can be simplified as material movement can be also logically separated from line to line. Data, activities, and control logics are coordinated and synchronized between lines using well-defined VPL formal models. The modularization and distributed computing is well known for promoting system scalability, flexibility, reusability, and reliability. For instance, when changes occur within a VPL, the impact onto the rest of the system is substantially restricted. An agent-based workflow management is incorporated in the proposed integration model to facilitate the timely delivery of data and information between the shop floor and a supply chain system. As a result, the manufacturing system governed by the proposed distributed MFM system is flexible, reconfigurable, and scaleable, ensuring the delivery of accurate and pertinent information to the proper users at the right time. From the technical perspectives, although the research shows some positive results as expected, many distributed computing issues should further be investigated before the developed system can be running as a mission-critical application in a real production environment, such as fault tolerance, interoperability, information security and assurance, and error recovery. Some preliminary investigations on resource sharing, WIP control and VPL design and operations algorithms have been conducted [13], [19] and [23]. Many other factors affecting system productivity should also be considered in the design and development of commercial MFM applications. To ensure such a system is practically applicable and sustainable, approaches to stimulating appropriate usages of information sharing along the supply chain should be investigated. In addition, a comprehensive framework for populating agents across other office-planning systems would be necessary as manufacturing enterprises are accelerating their e-business investment to meet the needs of future e-business.