A Study On Advanced Planning For Collaborative Production In Virtual Enterprise Based On Multi-Agent

With virtual enterprise's theory becoming popular, its operation experiencegradually enriching, and information technology speeding up, Virtual Enterprise (VE)has been the main organizational form for enterprises engaging in productionmanagement and participating in market competition in the 21st century. At the sametime, the development of VE has undergone the formation of conception and steppedinto the stage of practical operation. There is a strong need of pertinent theory andmethodology, which can guide the operation of VE. However, production planning isa core issue for the operation of VE in which collaboration is the key. Moreover, dueto multi-agent technology's function of collaboration and optimization, it rightlyfulfils the special requirement of VE in distributed and heterogeneous manufacturingenvironment. Therefore, after analyzing the characteristics and difficulties ofproduction planning in VE, a theory architecture about advanced planning system(APS) and a multi-agent based system reference model on advanced planning forcollaborative production in VE are presented. Based on the model, such crucial issuesas task decomposition and assignment, global production planning, partners' detailproduction planning and scheduling in VE are also studied. Finally, combining withenterprises' practice, a prototype system is developed to verify the theory and themethodology that are proposed in this dissertation systematically.Our research is carried out thorough problem, theory, methodology and practice,the main content or possible creativities of the dissertation are as follows:(1) Based on the analysis of the major process and characteristics of VEproduction planning, and the difficulties in drawing and implementing VE productionplanning, a theory architecture about APS and a system reference model on advancedplanning for collaborative production in VE are presented. The theory frame isconsisted of integrated management and collaborative optimization. Responsingqucikly to the customers' individualized requirement and promoting VE'scompetitiveness are its ultimate goals. Base on this frame, through analyzing thesystem requirement, a multi-agent oriented reference model on APS is proposed. Thereferential model covers three layers as a whole, namely, the resource planning, globalproduction planning and detailed production planning. It provides an implementalarchitecture for collaborative production planning in VE.(2) Based on the overall task of VE, task decomposition approaches and taskassigning models are studied. To support the operation of resource planning, takenminimizing the tasks' manufacturing cost as optimization object, a mathematicalmodel on resource selection is supplied and an ant colony optimization algorithm withcross operator is presented. Then, the formal negotiation models, negotiationprotocols and negotiation decision models for multi-agent adapting to VE environment are investigated, which can be employed to solve the problems thatmathematical programming approaches cann't in VE task assigning. Thereafter, basedon the price negotiation of task, probability function is constructed as offer andcounter offer strategies of agents and the expected price of both sides in the next turnsand their reserved price are also taken into account, an extended contract-net basedprice negotiation algorithm is put forward to make joint gain in VE.(3) Through the analysis of collaboration problems within VE members andbetween them, and the application of PSL ontology, XML and other technologies, thedescription of process information on syntax and semantic level is implemented. Sothe description of workflow is well-formed. Based on that, by employing FIPA ACL,CORBA and multi-agent technologies, a collaboration model for VE workflow isconstructed to support collaborative production operation in VE. Then, an easyplanning algorithm on fluctuated start and end time based planning problem is alsoproposed. Moreover, a mathematical model on tasks planning is presented with regardto the characteristics of VE production planning, and based on the coding of tasknumbers, a hybrid genetic algorithms (HGA) is presented. It combines geneticalgorithm (GA) excelent whole search ability with simulated annealing algorithm (SA)efficiently avoid getting into part minimum, thus the global searching ability of HGAis improved. The numerical simulation shows the good convergence and effectivenessof this algorithm.(4) On the basis of VE members' production planning and scheduling, themethods of multi-agent based production planning and scheduling, the ability of orderdealing and the bidding mechanism of negotiation are discussed. Taken into accountthe batch of job, task order constraint, the capability constraint and bottleneckconstraint of manufacturing resource, taken minimizing the tasks' manufacturing costas optimization object, a production planning model achieving ability balance isprsented. A genetic algorithm based on priority coding is designed to solve the modeland it is validated by the numerical simulation example. In addition, based on all sortsof problems of task rescheduling, the relevant strategy and process of reschedulingbased on multi-agent are put forward.(5) By employing agent oriented programming (AOP) methodology, a prototypesystem on advanced planning for collaborative production in virtual enterprise(VEAPS) is developed. The simulation result shows that studing collaborativeproduction planning based on multi-agent technology is both viable and effective.