Criterion – a way of comparing alternatives. Necessary to distinguish between the concept of the criterion and the criterion function. As an alternative criterion can be any sign of her, whose value can be fixed in the order or stronger scale. After the test is generated, ie, we find the characteristic that will be used as a basis of comparison of alternatives, it is possible to put the problem of choosing and optimizing. The problem of forming criteria resolved directly after the stated goal of systems analysis. The situation becomes clear if the criteria apply to both quantitative models of qualitative goals. Task system analyst is to formalize a problematic situation that arises in the course of systematic analysis.
This goal as time and serves as a stage in the formation of criteria. Formed criteria in some sense be a substitute goal. From The criterion requires the greatest possible similarity with the objectives to optimize the criteria consistent with closest approach to goals. In fulfilling this stage, it is necessary to recognize that the criteria can not fully coincide with the goals. One reason for this is that the criteria and objectives are formulated in different scales: objectives ratings, criteria in stronger admitting ordering. A criterion is a mapping of values embodied in the order on the parameters of alternatives that allow ordering. Defining the criteria values for this alternative is an indirect measurement of the degree of its suitability as a means to an end. Solving the problem Systems Analysis, a situation arises where it is impossible to propose a criterion to adequately reflect the purpose of the study.
Even one goal can rarely be expressed in one criterion, although this should be pursued. Criterion as and every model is only approximately reflects the purpose, the adequacy of a single criterion may be insufficient. Therefore, the solution may not necessarily looking for a more adequate criterion, it can be expressed in using several criteria, which describe the same goal in different ways and complement each other. Even more complicated problem when formulated several objectives of systems analysis, reflecting the different systems values. In this case, the researcher even more compelled to form several criteria, and subsequently solve the multiobjective problem. Thus, it can be noted that multi-criteria is a way to improve the adequacy of the objective. The criteria must describe if possible, all important aspects of the goal, but it is desirable to minimize the number of required kriteriev.Formirovanie criteria reflects the goal that puts the customer. But in the formulation and solution of problems in system analysis must consider not only the purpose for which it seeks a solution, but also the opportunities that have a hand for the task, and which allow to remove identified problems. The first thing to take into account the resources available to the parties. In formulating the problem of system analysis must also consider the interests of the environment. Environment plays a passive though role, but be aware that any system exists within it, interact with it. Therefore, in formulating the problem of system analysis should follow the principle of do no harm, not to take anything would be contrary to the laws of nature. The main criteria used most frequently in the analysis of complex technical systems. This economic criteria – income, profitability, cost, technical and economic – performance, reliability, durability, technological – out of the product quality specifications, etc.