Flexible Job-shop Scheduling Problem Under Fuzzy Environment

Flexible Job-Shop Scheduling Problem(FJSS) in fuzzy environment is one of the most important issues in practical flexible manufacturing systems,chich extends and developes from classical job-shop scheduling (JSS) problem. JSS problem is a classic problem and is still a hotspot,however,restricted by fixed machine route, JSS model does not accommodate to flexible manufacturing environment. FJSS extends the JSS by allowing an operation to be performed on more than one machine,which considers the flexibility of pratical manufacturing system and it press close to real environment , which has very important vaule in theory and Engineering meaning.Most researches about FJSS Problems are limited in strict restricted enviroments in which all kinds of information and restrictions are predefined. However, affected by humen,machines and envirmental factors ,the corresponding information such as restrictions and temporal parameters are uncertain.and can not be predefined precisely. This dissertation extend FJSS Problem form ideal environment to practical fuzzy environment which are more flexible and practical.First, this dissetation studies the Total Flexible Job-shop scheduling Problem aiming at minimized makespan which has fuzzy operation time and fuzzy operations intervals.Introducing fuzzy theory and possible theory ,it use the the signed distance measure and the credibility measure and other methods to illustrate each sub-problem of this problem and it use genetic algorithm to get perfect scheduling schemes respectively.Then, this dissertation studies the Partial Flexible Job-shop scheduling Problem which has fuzzy operation time and which aims at minimized makespan . For this problem,it introduces triangle fuzzy number to denote time parameters,and it studies a pretreatment algorithm to change Partial Flexible Job-shop scheduling Problem into Total Flexible Job-shop scheduling Problem,then an improved genetic algorithm is given to get a perfect scheduling scheme.Finally, this dissertation studies the Flexible Job-shop scheduling Problem...