Identification of dependability indicators of manufactured samples of radioelectronic systems

The article deals with the identification of dependability of manufactured samples of radioelectronic systems. This task belongs to the class of a posteriori analysis. In order to identify the dependability characteristics of equipment, upon production of a pilot batch one performs a posteriori analysis whose first stage is the statistical test (ST). There are a lot of methods for such tests that primarily depend on identifying the time of test completion (r – to failure of r systems, T – upon reaching operation time T, n – to failure of all systems, as well as mixed ones) and the ability to replace failed systems with healthy ones. Such tests are necessary because at the design stage a designer does not possess complete a priori information that would allow identifying the dependability indicators in advance and with a sufficient accuracy. An important source of dependability information is a system for collection of data on product operational performance. There are two primary types of dependability tests. One of them is the determinative test intended for evaluation of dependability indicators. It is typical for mass-produced products. Another type of test is the control test designed to verify the compliance of a system’s dependability indicators with the specifications. This paper is dedicated to the first type of tests. It shows the procedure for statistical tests of radioelectronic systems using various procedures. Evaluation of the mean time to failure is usually performed by means of the method of maximum likelihood. The essence of the method is that in the process of statistical data processing the likelihood function is found, while the required parameter ( is the evaluation of parameter t*) equals to the argument value under which the likelihood function is maximal. The evaluation of the mean time to failure is a point estimate of the initial parameter t*, which in turn is a random value and within a specific test can take any positive value from 0 to ∞. Therefore, in addition to the point estimation an interval estimation of the measured parameter is usually performed. That means that estimation identifies the confidence interval ( ) in which the value of the measured parameter t* with a specified probability is found. Here are respectively the lower and upper limits of a confidence interval. The article considers two procedures of testing pilot batches of radioelectronic systems, and for each of them the following dependability indicators are defined: evaluation of mean time to failure; confidence interval of mean time to failure. It is shown that for the purpose of identifying the mean time to failure, test procedure [n, V, r] is more efficient than procedure [n, B, r].

1. Zhadnov VV, Polesky SN. Proektnaya otsenka nadiozhnosti radiotekhnicheskikh sistem [Engineering estimate of dependability of radiotechnical systems]. Yurkov NK, editor. Nadiozhnost i kachestvo, tr. Mezhdunar. simpoz.: v 2 t., Vol. 1 [Dependability and quality, Third International symposium: in 2 vol., Volume 1]; 2006; Penza, Russia. Penza: Penza State University Publishing; 2006. Russian

2. Zhadnov VV, Sarafanov AV. Oupravlenie kachestvom pri proektirovanii teplonagruzhennykh radioelektronnykh sredstv [Quality management in the design of thermally loaded radiolectronics facilities]. Moscow: Solon-Press; 2004. Russian.

3. Artiukhova MA, Zhadnov VV, Polessky SN. Metod uchyota vliyaniya sistemy menedzhmenta nadyozhnosti predpriyatiya pri raschyotnoj otsenke pokazatelej nadyozhnosti ehlektronnykh sredstv [Method for accounting of the impact of enterprise dependability management system in estimation of dependability indicators of electronic facilities]. Radioelekpronika, informatika, ouparvlinnia [Radioelectronics, information technology, control]. 2013; 2:48 - 53. Russian.

4. Filippov BI. Apriornyj analiz nadyozhnosti radiotekhnicheskikh sistem bez vosstanovleniya [A priori dependability analysis of radiotechnical facilities without recovery]. Izvestia VolgGTU, seria Elektronika, izmeritelnaya tekhnika, radiotekhnika i sviaz [Journal of the Volgograd State Technical University, Electronics, Measurement Technology, Radio Technology and Communication Series]. 2015; 11 (176): 97 - 111. Russian.

5. Filippov BI. Aposteriornyj analiz nadyozhnosti radioelektronnykh sistem [A posteriori dependability analysis of radiotechnical facilities]. Vestnik AGTU, seria Oupravlenie, vychislitelnaya tekhnika i informatika [Journal of the Astrakhan State Technical University, Control, Computer and Information Technology Series]. 2015; 9: 81 - 91. Russian.

6. Nadiozhnost ERI: Spravochnik [Dependability of electronic components: Reference book]. Moscow: Ministry of Defense Press; 2006.

7. Levin BR. Teoria nadiozhnosty radiotekhnicheskikh sistem [Dependability theory of radiotechnical systems]. Moscow: Sov. radio; 1978. Russian.