# Smolkin V. P. RELIABILITY ANALYSIS OF FOREIGN PERSONAL COMPUTERS

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## Smolkin V. P. RELIABILITY ANALYSIS OF FOREIGN PERSONAL COMPUTERS

The key figure of the equipment safety is reliability. For unrepairable equipment parts and repairable parts till their first failure, reliability is defined by three parameters:

-survival probability

-average time of no-failure operation

-failure rate.

Besides, the property of repairable equipment parts, which defines the duration of their work between failures is specified by:

-mean-time-between failures

-failure flow parameter.

Numerical value of each of the parameters for any equipment is its reliability characteristic. The reliability characteristic analysis, based on theoretical premises offers a complex problem, since it requires affect accounting of numerous factors, conditioned by material properties, structural features, external action intensity. etc. As an example, one can note six factors, which affect a computer operation and each of these factors is able to damage it:

-extremal temperatures,

-dust,

-noise interference,

-mains supply break down,

-corrosion,

-magnetic fields, and also subjective operational factors.

Therefore, the reliability characteristics, even for simple computer components are obtained on the empirical data basis. With this, it is insufficient to test only one computer for getting the reliability characteristics, since even the same computers have different reliability because of the spread in parameters and different quality of their elements and materials. Although, nowadays there is no any method for reliable determination of the computer reliability characteristics beforehand, one can obtain their probability values, if one has some information on test results or numerous computer operation. A body of mathematics for reliability calculation in this case must be the probability theory and mathematical statistics.

One can perform the reliability calculation at different life cycle stages:

-while designing, on the basis of the reliability analy­sis for every equipment component,

-while carrying out tests of definite equipment quantity, presented for tests,

-on the basis of the equipment operation analysis. The reliability calculation of the foreign personal computers needs to be done only on the basis of the personal computer operation analysis, since:

1. The reliability of the foreign personal computer compo­nents is unknown and there are no any data in the national or foreign literature. It is very likely, that this information is a commercial secret of companies, engaged in accessory parts production.

2. There are no information regarding test performance of the foreign personal computers, though certain articles appear in the national press.

Therefore, the reliability calculation of the foreign personal computers is made on the basis of their operation analysis

## THE AUTOMATED SYSTEM OF CURRENT RATING

Contemporary corporate automated managerial systems of enterprise give an opportunity to collect, to store and to transform accounting information to the mode suitable for making managerial decisions. The final decisions are made by man , so the systems work in the interactive way. The increase of efficiency of management may be achieved at expense of current correction of managers’ knowlege about significance and mutual influence of different decisions. The significance is considered according to the aims of the enterprise and is formulated by the financial indicators [1].

The automated system of current rating of managerial tasks is worked out. The system has the following entries:

1. the vector of modules of the organizational structure of enterprise;

2. the matrix of mutual impacts of financial indicators ÌÂÂ with the dimension (mxm), where m is the number of financial indicators modelling the aims of this module. This matrix is imported from the system of automated accounting;

3. the fuzzy matrix of tasks ÌAA with the dimension (nxn), where n is the number of managerial tasks solved by this module. This matrix presents incidences of the multitude of managerial tasks by themselves. The elements of this matrix are entered by the manager of a certain level;

4. the fuzzy matrix of tasks ÌAB with the dimension (nxm). It presents the incidences of the multitude of managerial tasks by the multitude of financial indicators of this module. The elements of this matrix are also entered by the manager of a certain level.

The methodology of detection of lost influences is realized in the suggested system. The maxmin multiplication with the incidences of the third degree is constructed according to this methodology [2]:

ÌÀÂ= ÌÀÀÌÀÂÌÂÂ (1)

The matrix ÌÀÂ displays more precise incidences of the multitude of managerial tasks on the multitude of financial indicators of this module and therefore on the aims of the enterprise. The procedure of calculation of the ratio of managerial tasks is realized on the base of the matrix ÌÀÂ.

The automated system of current rating of managerial tasks has the following exits:

1. the matrix ÌÀÂ allowing the manager to see deviations of his knowledge from the real state and to understand the causes of these deviations;

2. the vector of managerial tasks with elements which are odered according to their ratio.

The system has been tested on the data of a certain enterprise which produces and realizes its producs.The directories of modules of the organizational structure, their managerial tasks and financial indicators have been completed in the process of setting.

For example, as to the modules «Shop» the following tasks have been determined:

1. the equipment; 2) the receiving and preparing of goods for realization; 3) the service of buyers; 4) the monitoring of goods and cash; 5) the collecting of marketing information.

Besides, the following financial indicators have been determined : 1) the taxes; 2) the sales; 3) the carring value of the equipment; 4) the purchase price of goods; 5) the markup on goods.

As a result, certain problems of business activity of the enterprise have been solved. Thus, the tools to increase the efficiency of enterprise with the help of the current rating of managerial tasks on the base of accounting information are worked out.

References

1. Хан Д. Планирование и контроль: концепция контроллинга: Пер. с нем. - М.: Финансы и статистика, 1997. - 800с.: ил.

1. Кофман А., Хил Алуха Х. Модели для исследований скрытых воздействий: Пер. с исп. – Мн.: Выш.шк., 1993. – 160 с.