Abstract In this article, we survey the developments with respect to generalized models of repairable systems during the 1990s, particularly for the last five years. In this field, we notice the sharp fundamental problem that voluminous and complicated models are proposed without sufficient...

Abstract A non-homogeneous Markov model is used to obtain closed form solutions of the state probabilities and the reliability of M modules in series where each module has N m components in parallel. The components have exponential time-varying failure rates which depend on the module. If the...

Abstract In this paper we provide a method of finding exact designs for single sample acceptance sampling plans. The method uses an algorithm that allows determination of plans based on the hypergeometric, binomial or Poisson distributions. Designs can be found for specified OC curves of either...

Abstract This article presents the method how to design a R control chart by variables, assuming that the quality characteristic that is being controlled follows a Γ-distribution. The use of an R -control chart shall be complementary to the application of a control chart for the process...

Abstract Process control by means of a p -chart or np -chart becomes almost impossible, if the quality level of the process in question is very good. However, if the quality characteristic is measurable then by narrowing the given tolerance limits and using accordingly changed gauges one can...

Abstract PISA stands for “Programme for International Student Assessment” performed, by the OECD and consisting of a cyclic evaluation of the new generations' basic competences. The first evaluation took place in 2000 and the results were published on 4 December 2001. According to the...

Abstract Statistical process control is a major part of industrial statistics and consists not only of control charting, but also of capability analysis, of design of experiments and other statistical techniques. This paper reviews and comments some available techniques for the univariate as...

Abstract For deriving the steady state probabilities and the availability of K -out-of- N : G systems with constant failure rate and general repairs an imbedded Markov chain at repair completion epochs is used. The special cases of constant repair time, Coxian-2 and Erlang-2 repair time...

Abstract This paper introduces a new designing methodology for Tightened Normal-Tightened ( TNT ) sampling schemes, indexed by an entry parameter called the crossover point ( COP ). The significance of the COP and the properties of the Operating Characteristic ( OC ) with respect to it are...