【正文】 nowledge from diversifiedfields. Generally, a machining process planning includes the following parts:fl feature recognition。 CIM1. IntroductionProcess planning provides information to theshopfloor on how to produce the designed products.It addresses each part of the product separately andcollectively. It defines the process, cost and production lead time under the constraints such as thedesigned geometry, material, quantity, machine andtooling availability, labour capacity and suitability,) Corresponding author. CIDAM Centre for Intelligent Design,.Automation and Manufacturing , City University of Hong Kong,Tat Chee Avenue, Kowloon, Hong Kong, China. Tel.: q85227888061。 Cooperative agent。 .Computers in Industry 41 2020 83–97A cooperative agent modelling approach for process planning. Zhao, . Tso), Paul . WuDepartment of Manufacturing Engineering and Engineering Management, City Uni?ersity of Hong Kong, Tat Chee A?enue, Hong Kong,ChinaReceived 30 November 1998。 accepted 25 January 1999Abstract .A well designed puteraided process planning CAPP system bridges the gap between CAD and CAM. A number ofsystems have recently been developed relying on a standalone expert system. However, because of overplexity, manysuch systems cannot be effectively applied to industrial enterprises in practice. Moreover, the modern puter integrated .manufacturing system CIM requires the CAPP system to be extendible and flexible for practical industrial applications. Itis hardly possible to develop the extensive industrial CAPP system by using only one large expert system. To overethese weaknesses, a new cooperative agent model is presented for process planning in this paper that satisfies five majorrequirements: Autonomy, Flexibility, Interoperability, Modularity and Scalability. In accordance with this framework .proposed, a machining cooperative process planning system Machining CoCAPP is specifically developed for demonstration purpose. The system modelling, agent structure design, cooperation and coordination mechanism, and case study of theMachining CoCAPP are presented. q 2020 Elsevier Science . All rights reserved.Keywords: CAPP。 Modelling。 Fax: q85227888423。fl machining operation selection。fl cutting tool selection。fl sequencing operation and cost estimate.The feature recognition part identities manufacturing features from the product design data. The machining operation selection part selects the relevantmachining operation according to the feature characteristics and the manufacturing environment. Therequired machine equipment is selected for implementing the selected operations after considering thenature of the parts and the machine processing capabilities such as the working volume, accuracy, power,fixturing, and other functions. The fixture selectionpart chooses the fixtures according to the part geometric shapes and dimensions as well as manufacturing features. The main concerns of the cutting toolselection include the tool types, materials, shapes,and tool dimensions.3. The proposed methodFrom the technological viewpoint, CAPP is still avery plex and difficult problem. Many researchefforts have focused on CAPP system development,using different methodologies and strategies. However, most systems are developed by using standalone expert systems. Due to the plexity ofCAPP, such a system structure is hardly able to solvethe problems normally found in the manufacturingindustry.A cooperative CAPP framework is proposed toreduce the limitation of currently available CAPPsystems. In particular, it highlights the requirementsthat a modern CAPP system should meet in order tofacilitate practical development: flexibility, modularity, interoperability, autonomy, and scalabilitywx15,16 .fl Autonomy means that the CAPP system isdeveloped as an independent system. Once developed, it can readily be integrated into the CADrCAM(). Zhao et in Industry 41 2020 83–97 85system. Each agent is also treated as an independentand autonomous system.fl Flexibility permits new technologies and newmethods to be easily added into the CAPP system.fl Interoperability permits multiple heterogeneous machines or approaches to work smoothlytogether in solving problems.fl Modularity enables the CAPP to function as anintegration of multiple subsystems.fl Scalability offers the ability to scale the CAPPsystem architecture according to the user’s transaction requirements.The design of the CoCAPP framework is discussed with relation to a machining process planning .Machining CoCAPP . Its structure, implementation,and its application case study are detailed in thispaper.. O?er?iew of Machining CoCAPPThe overall structure of the Machining CoCAPPsystem in the integration environment of CADrCAPPrCAM is shown in Fig. 1. The following six .process planning agents Pagents are in generalincluded in the implementation.fl feature recognition agent。fl machine selection agent。fl fixture selection and design agent。 when an agent sends a message, it directs itto the intended outgoing link. Messages to a singledestination arrive in the order they were sent。 fl PART Name。 MaxSize。 InitSta.tus。 Features .The Name is the identifier of a part. It must beunique. The Type is the keyword of the part to showits outlook shape. The MaxSize gives the maximumenvelope size of the part. The Material is the material kind of the part. The InitStatus is the raw status(). Zhao et in Industry 41 2020 83–9788of workpiece with which the part can be fabricated.The HeatTreat is about the part heattreatment condition. The Features are a collection of all features. Afeature is represented as follows: fl FEATURE Name。 Location。.InitSize。 TolerancesThe Name is the identifier of a feature. It must be