Flow Assembly Production Planning And Scheduling For Mechanical Products Based On State Tree And Time Dispose

In the 21-st century, with rapid development of information technology, the procedure of the globalization and integration of the world economy has been speeded up, and the time-space environment of the economy has been fundamentally altered. PPS(Production Panning and Scheduling) has become more and more importance in the management of the modern manufacturing. Using the relevant theoretical research achievements for reference, and aiming at the small and middle-sized enterprises in mechanical industry, the PPS of the flow assembly line is deeply researched in this dissertation. Based on the time interval algebra which was presented by Allen, the time relationship theory about production management is systematically expounded. Three concepts have been given: time, time point and time interval, and the expressions of them are normalized. The time relationship among them has been analysised and summarized across-the-board, and the expression of each relationship is given. Therefore, a powerful theoretical tool has been provided for the time disposal in PPS. Referring to the relevant theoretical and practical research achievements, and completing detail study in the assembly production process of products, the assembly state tree concept is presented. The three-hierarchy architecture of the PPS system based on product sequence and the WIP(work-in-process) dynamic monitoring system of the flow assembly line have been constructed. At the same time, mathematical analysis method for the state of assembly production is dissertated at length. Some new concepts are presented, such as: state array, location array and control vector, which are applied to describe the assembly production process successfully. The method for production planning which is based on time interval disposal is presented, and the pretreatment of producton planning is also discussed. The net need for production is figured out through the pretreatment. According to the net need, the production is planned by adjust the production time of the first workstation of the assembly, and the results are consistent with the actual production. A method for calculation of material requirements based on ABOP(Assembly Bill of Process) is presented for assembly production. The material consumption procedure of the assembly production is divided into branch stream and node stream, and then subdivided into unit requirements. Each unit requirement is a set of materials which are needed by the production of a certain workstation when a product is processed there. In terms of the conception of ABOP, the calculation method of material requirement is discussed, and is divided into two different ways: the method based on node stream and on tact stream. Besides, the method based on node stream is flexible in different time precision. Some techniques of the production monitoring for flow assembly line are addressed in this dissertation, including: the method of make production demand, state tracing of WIP, state control of WIP and so on. In addition, in the case of urgent ordering, the tactics and the method for dynamic production scheduling is illuminated in detail. Aiming at production planning, production tracing and controlling, material requirement planning, using the ZOPE network platform, a prototype system for the PPS system of assembly production is implemented, and validates the feasibility of the methods and the principles mentioned. Moveover, some of the methods and the strategies have been applied in practical production manament.