【正文】 osal is then notified.If a conflict is notified from another agent, theconflict resolution responds to this event to resolvethe conflict. After the adapter responds to the conflict event, it first judges the conflict situation. Thenit invokes the relevant strategy to resolve the conflict.. Knowledge representationThe CoCAPP system’s knowledge is about product representation and agent knowledge. Each Pagentin the CoCAPP system has three types of knowledge: domain knowledge, control knowledge, andconflict resolution knowledge. The Bagent has onlycontrol knowledge. The part representation is aboutthe problem description. It is monly shared byall agents within the CoCAPP system.. Part representationA part in the Machining CoCAPP system consistsof two kinds of data. One kind is about the constraints to the generating plan. Another kind is aboutits geometric information. They are described asfollows: fl CONSTRAINT production time, cutting force,.machining power 。 Type。fl evaluate proposals。Pa。fl resolve conflicts.The above tasks are scheduled before they areperformed. Each task is scheduled as an event. ThePagents first respond to an event, then perform therelevant tasks. The control knowledge of the Pagentsis used to schedule tasks and to respond to events.Each task is assigned a priority as an event. Aspreviously discussed, the negotiation is the highestpriority task. The conflict resolution shares the second highest priority. The proposal evaluation has thethird highest priority. The proposal generation hasthe lowest priority. The scheduled tasks are performed asynchronously. The event is responded toaccording to the principle of ‘first e, first served’.. Planning strategyThe CoCAPP system solves the process planning problem, using coordination and cooperationbetween the Pagents through a monly sharedlanguage with the expectation about how to reachagreements when conflicts occur. Therefore, thesystem is designed to support cooperative problemsolving by providing a munication and conflictresolution structure and the protocol required forcooperative interaction.. DefinitionwxAccording to Ref. 23 , the problem, proposal,evaluation, and conflict are defined as follows: Suppose that a problem is represented as P s 4Or,G,C, I , where Or denotes the originator of theproblem, G is the set of goals of process planningproblem, C is the constraints for this problem, and Icontains the initial information such as part design data. A proposal is in the form of Qs 4Ow_P, Ac_P, Exp_Q,Cf , where Ow_P denotes theowner of the proposal, Ac_P is a set of actions tosolve the given process planning problem, Exp_Q isthe explanation to the proposal, and Cf is the confidence factor for the proposal. An evaluation result can be represented by E? s Ow_E?,4Id_Q, Ac_E?, Ra, Re , where Ow_E? denotes theowner of the evaluation, Id_Q is the identity of theproposal Q, Ac_E? is the set of evaluation actionsfor the proposal, Ra is the set of ratings for eachaction, and Re is the overall result for the proposalwhich is either disagreement or agreement. When Resays disagreement, a conflict appears, expressed in 4the form Cr s Ow_Cr, Id_P, Ac_Cr, Exp_Cr ,where Ow_Cr denotes the owner of the conflict,Id_P is the identity of the related proposal, Ac_Cris the set of conflict actions, and Exp_Cr is theexplanation for the conflict actions.The problem solving is initiated by the Dagentaccepting a problem and putting the problem defini 4tion Ps Or,G,C, I into the problem area of theBagent. All registered Pagents are notified of theproblem information. The interested Pagents willexamine the problem definition and start producingplanning proposals related to their expertise, knowledge and viewpoints. When a Pagent generates a 4proposal Qs Ow_P, Ac_P, Exp_Q,Cf , it is putinto the proposal area of the Bagent. The proposal isposted to other registered Pagents. A Pagent is notinterrupted if it is already working on another proposal, but immediately triggers an evaluation thread.This thread first determines whether it is going tocriticize the proposal. If not, it will go to sleep andwait for another proposal to be asserted. If thePagent is interested in the proposal, it then evaluatesthe proposal and posts the evaluation result E?s 4Ow_E?, Id_Q, Ac_E?, Ra, Re into the evaluationarea of the Bagent. If there is a conflict, the resultCrs Ow_Cr, Id_P, Ac_Cr, Exp_Cr will be examined in order to obtain the final evaluation result.After all the interested Pagents finish evaluatingthe newly asserted proposal, those Pagents whichidentify the proposal under consideration as conflictwork together to resolve the conflict Cr s 4Ow_Cr, Id_P, Ac_Cr, Exp_Cr . The result of theconflict resolution is either a revision or an abandon(). Zhao et in Industry 41 2020 83–9790ment of the proposal scheme. When none of theinterested Pagents detect any conflict related to theproposal, the partial planning template residing in thesolution area is updated. The planning process continues until the planning template meets the requirements, including planning goals and constraints.. CoordinationThe cooperative problem solving is carried outamong the Bagent and Pagents. The Bagent isresponsible for storing and announcing the publicinformation involved in each process planning problem. It is partitioned into four areas for four distinctgroups of information: problem, proposal, evaluationand solution. The problem area contains the initialproblem definition and the overall requirements ofthe process planning problem. The proposal areastores partial and plete proposals at several layers of abstraction issued by the Pagents. A proposalfrom a Pagent might be evaluated by