System approach and probabilistic methods

A systematic approach involves the consideration of objects in the relationship and development. In this regard, we note that the characteristics and parameters of the RES are determined by the interaction of many parts or subsystems (elements), each of which in turn can be represented as a set of subsystems of an even lower hierarchical level. For example, the following hierarchical sequence can be presented in an EF: materials, technological processes (equipment and tools), parts, elements, electrical connections, supporting structures, RES. At each of these levels, one has to deal with random deviations, impacts, interactions, etc. In addition, there are processes of state changes over time (the development of degradation). Parameters at all levels should be considered as random events, values, processes, which are usually regulated by tolerances.

External influences have a random nature; random values ​​describe troubleshooting and repair time, time to failure, etc. Only some indicators, such as mass, dimensions, power consumption, frequency range, and others, can be practically expressed deterministically. without using probabilistic concepts. This leads to the need to use probabilistic concepts and representations . Probabilistic methods can be defined as methods of research, calculation, analysis and synthesis based on the use of probabilistic concepts, models and patterns, their transformation and interpretation, using the results of statistical observations and their processing .

The use and role of probabilistic methods in the design of radio electronic devices.

The increasing complexity of the designs and technologies of the RES, the use of the most complex physical processes characterized by a significant “number of degrees of freedom” in its manufacture and operation, led to the fact that, guided by the system approach, it is no longer possible to abstract from random deviations and changes in the parameters and characteristics of the RES and their elements, as well as from the influence that these “deviations and changes have on the main indicators of the quality of the distribution zone, such as reliability, stability of parameters, operating costs etc. The deviation and instability of the RES parameters is largely determined by the design and technology, it is in this part of the designer-technologists that have one of the main influences on the development of the RES and quality indicators .

The use of probabilistic methods is caused by the following main reasons:

1 . The operation of many RESs and their elements is based on the use of complex physical phenomena, in which the useful effect is formed by the cumulative effect of many elementary formations that are in complex random interaction with each other.

2. In those cases when relatively simple physical phenomena are used for the operation of the RES and elements, for which unequivocal laws are found, they face the fact that during the manufacture of the RES there are a large number related to the production technology (purity of materials, state of the tool, etc. .) “Degrees of freedom”, the determination of which is not economically feasible and organizationally difficult. Then the parameters and characteristics of XPS also turn out to be random variables and functions.

3. In some cases, the physical process that determines the manufacture and operation of the RES or their elements has not been fully studied, but statistical stability is practically observed, which allows the experiment to find and then use quantitative characteristics of the RES and their elements based on probabilistic representations.