Materials Engineering, Vol. 17, 2010, No. 4 28 THE ROLE OF OBJECTIVE FUNCTION IN ENGINEERING DESING Robert Ulewicz 1* , František Nový 2 , Magdalena Mazur 3 Received 29 th November 2010; accepted in revised form 9 th December 2010 Abstract The process of material choice is a key element in the production of machines, devices and other engineering constructions. Engineering design relates to the design of engineered artifacts formed by materials of various types. Materials play an important role during the entire design process. At the early design stage, materials may achieve some of the required functions. Therefore, designers may need to identify materials with specific functionalities in order to find feasible design concepts including the costs of material and technology. In this paper, an overview of research in materials identification and materials selection is introduced. The objective function was used in the material selection. The assumed demands in industrial practice were verified by means of criteria patterns. Keywords: Objecive function, engineeing desing process, materials identification and selection. 1. Introduction The choice of a proper material for constructions is a very crucial element in a designing process. It is well understood that materials play an important role in engineering design. Materials are generally regarded as the attributes of a physical structure, thus are often considered only after the physical structure of a design that was determined. That is to say, they are often considered after conceptual design stage, such as in embodiment design or detail design. At these downstream design stages, designers need to find materials with specific properties, which can be used to achieve the required system performance and/or other requirements. To this end, the design task is often focused on comparing the properties of a finite set of materials and selecting the best ones out of this finite set, namely, materials selection. Nowadays, the designers have to, appart from materials properties, take into account economic factors such as the cost of usage of such a material, technology costs, costs of influence on environment as well as utilization of post production waste costs. Fig. 1 presents the relevant information flow associated with key decision-making in the early stages of the design process including economic and environment problems. Fig. 1. The Design-problem solving. 1 Prof. P.Cz. dr hab. inż. R. Ulewicz – Czestochowa University of Technology, Department of Management, Institute of Production Engineering, 42-201 Czestochowa, ul. Armii Krajowej 19B, Poland. 2 F. Nový, Ing. PhD. – Department of Materials Engineering, Faculty of Mechanical Engineering, University of Žilina, Univerzitná 1, 010 26 Žilina, Slovak Republic. 3 mgr inż. M. Mazur – postgraduate Czestochowa University of Technology, Department of Management, Institute of Production Engineering, 42-201 Czestochowa, ul. Armii Krajowej 19B, Poland. *Corrensponding author, e-mail adress: ulewicz@zim.pcz.pl