The leaving century was "explosive" on rates of development fundamental and applied sciences, industrial and information and technologies. Representation about technology as to a science about machine-building manufacture is developed. This part of knowledge has remained is known both in professional, and in narrow-minded consciousness. The greatest investments have been addressed in this branch of knowledge at last decade the left century.
Experts on development of the industry already for a long time expected, that processes of development, preparation of manufacture, manufacturing, marketing and sale, operation and support submit to one natural laws and can be formalized in an obvious way.
Object of my master's work research is the machine-building enterprise, namely structure of its equipment. The purpose is development of the automated subsystem of definition of optimal structure of the equipment.
Definition of quantity and choice of types of the equipment necessary for performance of the set production program, is the basic and most responsible question at calculation of shop. Incorrectly counted up quantity or equipment incorrectly picked up on types entails surplus or lack, and also its shortage. There is its incomplete use of the equipment , the exaggerated and unproductive expenses for its purchase, installation and the maintenance, increase in the area which are required for its accommodation. At lack of the equipment there is no opportunity to carry out a production target. Inevitable necessity thus to add machine park causes greater difficulties owing to limitation of the area, and also difficulty with the arrangement caused by sequence of performance of technological operations. Correctly counted up quantity of machine tools should provide its completeness simultaneously. If machine the park is completed in such way, that separate groups of machine tools do not possess respective throughput the shop cannot let out the set quantity of finished goods as separate stages of processing will be late. At wrong selection of machine tools on types and the sizes for some operations it can not appear suitable machine tools.
The purpose of the given work is development of the automated subsystem of designing of optimum structure of the equipment of the machine-building enterprise. It is necessary to solve following problems for achievement of an object in view:
the Choice and a substantiation of criteria of an optimality of structure of the equipment
Development of statement of a problem of definition of optimum structure of the equipment;
the Choice of a method of optimization and its updating;
Development of the program module which reakize an object in view;
For the decision any optimization problems it is necessary to construct the mathematical model of investigated process consisting of a set of variables, influencing on this process, and the laws connecting these variables.
The model incorporates practical engineering designing features, for example considers productivity of machine tools, use of alternative machine tools (machines, mechanisms) from machine park, and the limited size of a cell. It integrates design decisions, having mechanisms in each cell and distributing the production program on the equipment, satisfying those machine capacities which provide machine loading sufficient for maintenance of necessary capacity and distributing manufactures between cells and the alternative equipment.
Last two decades by optimization of complex systems researchers even more often apply natural search engines of the best decisions. These are mechanisms provide effective adaptation of flora and fauna to an environment during millions years. Today scientific direction Natural Computing, uniting methods with natural mechanisms of decision-making is intensively developed, namely
- Genetic Algorithms ;
- Evolution Programming ;
- Neural Network Computing ;
- DNA Computing ;
- Cellular Automata ;
- Ant Colony Algorithms.
In spite of master’s work is in process of development, but it is possible to assume, that the task in view will be solved by one of the listed methods or its updating, owing to multicriterion models.
The program module which will be developed in this master's work will allow to solve quickly and effectively in practice approach to solve the general cell formation problem, namely to define optimum structure of the equipment.
Skinner [1974] was the first to propose the concept of a focused factory, in which small manufacturing systems operate independently within large production plants. The idea works best for medium-variety, medium-volume situations, that is, batch production. The focused factory is constructed using the notions of either flexible manufacturing systems (FMS) or group technology (GT), which are based on the precept that certain activities should be dedicated to a family of related parts in a manufacturing cell. Later Burbidge [1975] developed and popularized a systematic approach to this concept, which has subsequently seen widespread adoption in western industry.
Since machines are located in close proximity in a manufacturing cell and a family of related parts are produced, there is usually a reduction in: transport requirements, conveyance times, set up times, and inventory. Moreover, the relatively large autonomy within these manufacturing cells leads to extra motivation of the workers (who are responsible for “their products”), often resulting in higher productivity and product quality. These, and other advantages, have been discussed by Shunk [1985] and Hadley [1996]. However there are also disadvantages to this approach, such as the relatively costly duplication of machines.
FMS is related to GT in so far as both are sub-systems that represent “islands” within the production process, comprising groups of machines (sometimes including a material handling system), which produce a family of items. The main difference is that an FMS represents a fully automated system, whereas in GT conventional technology generally predominates. Most of the recent major results in the GT literature, concerned with the single criterion of minimizing inter- cell materials handling costs, have been discussed by: Billo [1998], Chu [1995], Kusiak and Heragu [1987], Selim, Askin, and Vakharia [1998], Vakharia [1986], Wemmerhov and Hyer [1987], and Wang [1998].
Suppose that a number of different products have to be manufactured using certain machine types. It is known from the process plans of the parts, which machine types are required for producing the individual parts, and the routing (machine ordering) for each part is given.
This leads to the following activities:
(a) Assign part families to groups of machine types,
(b) Find lot sizes of the parts produced,
(c) Determine the number of machines needed of each machine type,
(d) Assign parts to individual machines,
(e) Group individual machines into manufacturing cells, and
(f) Compute job schedules for the machines.
The so-called machine type-part incidence matrix specifies which parts must be processed by which machine types. It is desirable that the machine type-part matrix should be transformed into a block-diagonal form to solve problem (a) (see, for example, Askin and Standridge [1993], Kumar, Kusiak, and Vanelli [1986], Kusiak and Chow [1988], and Hadley [1996]). Each block then shows which family of parts is to be processed in which group of machine types.
If such a block-diagonal clustering cannot be obtained, activities (b) to (e) have to be carried out. Well-known methods from inventory control (Hillier and Liebermann [1995], Nahmias [1993], Domschke, Scholl, and Voss [1997], and Neumann [1996]) can be used to carry out activity (b). A method that includes specific information relevant to group technology has been proposed by Askin and Chiu [1990]. Given the lot sizes for all parts, we can compute the necessary utilization level of each machine type, which also provides the number of machines needed of each type, ie, the solution to problem (c).
Problems (d) and (e) have traditionally been solved separately. (See, for example, Askin and Chiu [1990], Askin and Standridge [1993], Cao and McKnew [1994], Faber and Carter [1986], Garcia-Diaz and Lee [1995], Hadley [1996], Kumar et al. [1986], Kusiak and Chow [1988], Moussa and Kamel [1995], Plaquin and Pierreval [2000], Neumann [1996], Vanelli and Hall [1993], Rajagopalan and Batra [1975], and Zhou and Askin [1998].) However, most solution procedures for problem (d) utilize a solution to problem (e) and vice versa.
This review was taking from article “Approaches to the general cell formation problem” by L/R Foulds and J. M Wilsom [2002]
The result of performance of work are develop the program module and to receive mathematical model of optimum structure of the equipment of manufacturing system with objectives: maximize the machine utilization rate, minimize the number of duplicated machines, and minimize the number of exceptional elements.
Rough in development of mechanical engineering and simultaneous sharp jump in post-war years have forced to think seriously of new, more precision ways of optimization of work of manufacture. In the given abstract I have tried to explain problems of my master’s works, to make the brief review of problems with multi-objective optimization, to tell about applied methods. This master’s work is planned to finish in November-December, 2007
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Книга посвящена принципам построения АСУ промышленных предприятий.
Уланов Г.М. : Москва; Энергоатомиздат, 1983 г
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В данной статье впервые авторы развивают многократный подход принятия решения критериев
чтобы решить проблему формирования производственной ячейки, когда имеются противоречивые цели.
"Approaches to the general cell formation problem"
L.R Foulds and J.M Wilson, University of Waikato, New Zealand and Bisiness Shool, Loughborough University, Great Britain
URL адрес
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Статья посвящена ГА и основным его операторам
"Эвалюционные вычисления"
Yuri Burger
URL адрес
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