Raising of the functioning efficiency of the automated information systems by planning the procedure of their improvement

Розглянуто принципи підвищення ефективності функціонування автоматизованих інформаційних систем на основі аналізу часу початку їх реінжинірингу, а також планування процедур удосконалення в цілому. Побудовано комплекс марковських і напівмарковських моделей для визначення показників надійності й продуктивності укрупнених кластерів автоматизованих інформаційних систем.Both, the principles of raising the efficiency of automated information systems functioning by analyzing the starting time of their re-engineering and improvement planning procedures in general are taken into consideration. The complex of the Markov and semi-Markov models to determine the reliability and productivity indices of enlarged clusters of automated information systems is built. To choose the depth (level) of penetration of reengineering procedures the quantitative and qualitative estimation is used. The depth of reengineering penetration is defined by the penetration coefficient correlated with the possible automation level of a certain system element in particular or the whole system in general. To determine the re-engineering starting time for the AIMS two approaches are used. The first one determines the best reengineering starting time by estimating the expenses increase on the system service. The second approach determines the average cycle time of the system on the basis of the semi-Markov model construction. The paper contains the numerical simulation of the distribution functions mean cycle time of dataset service for the Erlang distribution under the conditions defined mathematical expectation and variance for the time between failures, processing unit recovery time, set collection and dataset processing time Results obtained in our work limit the efficiency level of AIMS subsystems. For the systems with clear structural differentiation the estimation of the minimal acceptable level of the system performance indicator for each structural unit is done. As a result, the constraints ensemble was obtained. Thus, the obtained expressions for the structural components of AIMS can be used as limits of the effectiveness of these subsystems, when making decision on the whole system re-engineering. The novelty of this approach realization is the accounting of investments at the stage of the system functioning after the beginning of moral obsolescence and correlation of these expenses with the efficiency of the system ongoing improvement by estimation changes in the mean time of the system cycles. The total amount of efforts (financial, intellectual, creative) on continuous improvement determines the particular starting time and penetration depth of re-engineering procedures, which make possible to save due to the same factors providing the revolutionary change of the system modernization