معماری هولونیک از سیستم برنامه ریزی عملیات یکپارچه همزمان

This paper describes a conceptual architecture of applying holon to process planning (PP) for integrating design, PP, and shop floor scheduling so that a concurrent integrated process planning system (CIPPS) is constructed. The problem in PP has been mapped onto a holonic architecture based on multistage cooperation. A holonic architecture for CIPPS integrates all the activities of PP into a distributed intelligent open environment. Holons for CIPPS can be organized dynamically, and cooperate with each other to perform an appointed task flexibly. In addition, using CORBA technology, a prototype system of the CIPPS is implemented.

Traditionally, the activities of product design, process planning (PP) and shop floor scheduling are viewed as discrete stages in manufacturing enterprise and developed, respectively, into automation systems. However, decisions taken in one stage affect the decision in downstream stages [1]. Computer aided PP has been recognized as playing a key role in computer integrated manufacturing (CIM) that integrates these islands of automation. It forms an imperative connection between design and manufacturing operations in CIM. However, most of the PP is generated without consideration of real-time dynamic status information in the shop floor, and assumes an infinite capacity of resources on the shop floor, and usually a factory is empty without any work-in-progress when assigning resources to jobs [2] and [3]. These assumptions lead to the repeated commitment of certain popular resources to numerous process plans [4] and [5]. Over the past two decades, considerable efforts have been expended in developing integrated computer aided design (CAD) and computer aided manufacturing functionalities. Based on the philosophy of concurrent engineering (CE), a concurrent integrated process planning system (CIPPS) is proposed in this paper to integrate CAD, PP, and production scheduling system (PSS) so that it is expected to significantly enhance the ability of manufacturing companies to adapt efficiently to changing conditions, and yield significant performance improvements (e.g., shorter lead times, increased resource utilization, enhanced due-date performance and coordination between customers and suppliers). In order to implement CIPPS, a holonic architecture is presented, which has characteristics such as distribution, autonomy, interaction, and openness to meet the requirement of CIMS. The rest of this paper is organized as follows. Section 2 proposes a concurrent integrated PP model. Section 3 describes a conceptual architecture of applying holons to PP for integrating design, PP, and production scheduling. The needed holons are defined. Section 4 describes the cooperation between holons. Using CORBA technology, the CIPP prototype system is constructed in Section 5. Section 6 is the conclusions.

A problem in the traditional product development cycle is that the communication between different perspectives is linear in nature. This would lead to long and costly development cycles as design mistakes are often not discovered until the downstream stages of product development. This paper proposes a CIPP system. An initial testing phase of the CIPP prototype system has been completed in close collaboration with an industrial partner with very encouraging results. It is shown, first, to provide a tool for CAD by integrating downstream constraints into the design phase so that the need for redesign (due to design mistakes) later can be reduced in the product development cycle. Secondly, it integrates PP and production scheduling so that the CIPPS provides a process plan that optimizes due-date performance while minimizing manufacturing cost or lead time by taking into account alternative process plans and the real-time resource status in shop floor. Thirdly, it responds continuously to manufacturing conditions and production task changes with the help of these holons that can be organized dynamically, and cooperate with each other to perform an appointed task flexibly. Therefore, the development of holonic architecture for CIPPS satisfies the requirements of agile manufacturing: rapid response to changing requirement; reduction in both time and cost of the product realization process; and integration within a heterogeneous, wide-area networked enterprise.