Evaluation of Technical Resilience and Its Estimation by the Least Squares Method

Abstract

The resilience of technical systems is an internal characteristic whose values of reliability, maintainability and availability parameters must be estimated in the design process. The difficulty of this approach derives from the fact that the resilience parameters are influenced by the behaviour of the technical system during its operation. For this reason, an analysis of the technical resilience of a technical system in operation is required, the analysis that the present research also makes. The current work aims to provide a tool for analyzing the evolution of technical resilience parameters - reliability, maintainability and availability during the operation of technical systems, useful in the decision-making process of maintenance management. The main purpose of the work is to determine the evolution of the score of the resilience parameter of a technical system in the mechanical field during operation. The parameter, taken from the specialized literature, used for the calculation of resilience is based on the Safety in operation indicators - mean time between failures (MTBF) for system reliability and mean time to repair (MTTR) for maintainability. These two parameters were calculated from the data obtained after the operation of a honing machine, including information about the moments of appearance of the defects, the repair time and the type of defect. The resilience evolution is given by a regression line generated by the least squares method on the measured and calculated data series. The regression analysis proposed in this research follows the evolution of the values of the technical resilience parameter over the time horizon over which the technical system was observed in order to the maintenance management decision process for the analyzed system in accordance with the quality and production policies. The research methodology is specific to a quantitative analysis applied to a technical process, continuing the formulation of the problem, the literature study on the researched topic, the determination and analysis of the series of values for the evaluated parameters, and the generation of conclusions on the analyzed phenomenon. This research's results are compared with those from the specialized literature that evaluates technical resilience through metrics on different mathematical models. Also, the research results are essential due to the comparative analysis of resilience in systems from other technical fields.