Engineering Costs and Production Economics最新文献

In this paper a novel decomposition strategy for multicriteria optimization of large-scale systems is presented. The strategy has a heuristic character and contains four stages. The first stage is to optimize the overall system with respect to basic decision variables. The second stage is to optimize all subsystems which are considered separately. Interaction between subsystems and between the first and second stages are treated as coordination variables. The third stage is to optimize the overall system with respect to coordination variables. The final stage is to select the Pareto optimal set of solutions and to make final decision. An application of the strategy for designing machine tool spindle systems with hydrostatic bearings is presented.

This paper presents a development of decision support systems for solving scheduling problems. It consists of two parts — the first describing the production processes which can be handled by the system and the second describing how the system works.

This paper aims at introducing a formalized description of work in an industrial enterprise and using it for laying out optimal multi-period economic plans. In that description basic input and output variables, relations and connections with environment, all important technological dependencies and decision functions can be taken into consideration.

Industrial enterprises differ, for instance in size, assortment of production etc. We want to derive a solution useful for varied types of enterprises and that is why we introduce the concept of the manufacturing plant.

A new interactive hierarchical dynamic programming technique, briefly described in the paper, is applied to the solution of the problem. An example problem is formulated and solved with the following objectives taken into consideration: (i) minimization of utilization of deficit materials, (ii) maximization of production size, and (iii) maximization of profits.

We consider multi-objective, multi-period planning in the manufacturing plant as a deterministic problem.

Multicriteria shape optimization of a ceramic piston crown used in a medium speed diesel engine is considered in this article. The special features of ceramic materials, which suggest a different structural design approach for ceramics than for other materials, are explained. The basic ideas and equations of the finite element method (FEM) in the linearly elastic case are presented because the optimization and decision-making processes are closely connected with the numerical analysis of structures. A two parametric Weibull distribution is applied to the strength test results in order to assess the reliability of a ceramic component. Its complement, the probability of failure, is chosen as one criterion to be minimized. Another competing criterion is the material volume which usually is the only optimized quantity in structural optimization. Finally, a bicriteria problem for the piston crown is formulated in detail by using the locations of the control nodes, which by B-splines determine the shape of the crown, as the design variables. The technical background of the piston design problem is briefly discussed and some Pareto optimal shapes have been generated for the decision-maker.

Branches are used to represent decisions that can be taken during a particular period. A simple branch-and-bound procedure is presented that can be applied to single-item, single-level lot-sizing with back ordering under the conditions of variant holding, ordering, and shortage costs on a period-by-period basis. At the beginning of the procedure there are no stocks, then, three possible decisions can occur in any period. Yet, with some simple decision criteria, the rule can be simplified and presented as a decision tree in an easy form. The simplified algorithm is also shown in this paper with PASCAL language written modules.

Consideration of quality implicitly introduces the need to adjust inputs in order to obtain desired output. Output evaluation must consider quality as well as cost. Real decisions may involve other objectives as well. Production problems often involve a dynamic situation where the relationship between cost and quality must be experimentally developed. The proposed method is to use regression as a means of identifying input-output relationships, to include variance. A chance constrained multiobjective model can be developed, and decision maker preference incorporated through interactive analysis. Through application of the proposed method, efficient solutions providing as much quality as desired at minimum cost are capable of identification.

Past applications in the area are discussed, as are data collection, modeling, and solution procedures. A number of multiobjective concepts are reviewed in light of the chance constrained model. Constrained techniques are considered more appropriate than weighting techniques for this class of problem. The abilities of currently available solution techniques to support multiobjective analysis for this class of problems are also discussed.

A microcomputer-based decision support system (DSS) is developed to help the managers of medium-scale firms make decisions when faced with rapidly changing market conditions and to strengthen their production management problem-solving abilities. The system, designed for production management, includes three basic units: (i) the database, an information resource; (ii) the model base, a solution technique; and (iii) the interactive dialogue, a decision making procedure.

The database subsystem integrates the advantages of using a structure database to convert manual operations to computerized operations and provides up-to-date information. The model base subsystem is designed to minimize the inventory cost by considering two objectives. A heuristic procedure is also introduced to solve the large scale bicriterion integer programming model when used in a real production environment. The man-machine interactive dialogue is designed to allow communication with the system in an easily learned and approachable manner. The entire DSS is based on the practical operations of a medium-scale export commodity producer.

The selection of factors or variables constituting various performance criteria, such as productivity, effectiveness, efficiency, etc. is an important step in developing a performance/ productivity measurement system in an organisation, conceived essentially as multi-criteria decision making. The construction of the utility value function for variables on the basis of identification of a number of desirable outcomes and decision makers' preference leads to quantification of so called “intangibles”, measurement of these criteria in explicit terms, establishment of degree of relationships among them, and estimation of total performance of an organisation, manufacturing or service.

In this paper, four criteria of performance, viz., productivity, effectiveness, efficiency and quality of an organisation are defined in terms of specific outcomes the decision makers seek from them. The utility function of each variable is constructed by administering questionnaires on desirable outcomes to a group of managers/ supervisors in a division of an organisation. Significance of productivity in its ability to explain the changes of values of other performance criteria over time periods is tested, and explanations are provided. The relationship of a number of objectives of the division with the factor s of the recommended Overall System Performance Model is also explained.

Project Management in entrepreneurial economics is mainly a uni-criterion decision making process viz. the consideration of Net Present Value or Internal Rate of Return. When an industrial project however is brought at the level of government it is no more a uni-criterion decision making process. Indeed at that moment, certainly in developing countries, a lot of criteria have to be fulfilled.

As succesful applications of MCDM in this field are scarce, we present a proposal which was accepted by a government of a developing country. The proposal could be generalized for some other projects and it will be shown how multiple criteria decision making was involved. It also will be shown how the calculations were made to fulfill the criteria.

Some cost-effectiveness studies however concern several competing projects. At that moment the problem of optimization of several non-transitive targets is posited.