Reliability in random environment: Systemability and its application

Industrial manufactures of automatic machines meet troubles in predicting reliability performance of systems during operative conditions in customer applications. Environmental factors may change failure rate of components, reliability and availability. H. Pham [1-2-3] recently introduces a new model for estimating component reliability under random environmental effects, called Systemability. This approach appears very interesting and suitable for automatic machines because it separates the effects related to the machine components from the environmental factors. Reliability is the probability that a component, or a system, meets a determined mission, for a determined time and in determined environment. The operating environment is often unknown and it is different from the laboratory or standard environments. Therefore, in reliability engineering, conversion problems and synthesis of test results are often met from different environments. This paper presents the model applied to a real case study regarding the reliability analysis of an automatic filler that works in different systems, that operate in random environments, in different customer plants: the system packaging lines for production of beer. Many models of environmental factors estimation have been proposed: in this paper the adequacy of Systemability model to fit the observed data has been assessed. Furthermore, some suggestions are shown in order to continue the research in this field.