MODELS IN MECHANICAL RELIABILITY DATA

The mechanical reliability uses many statistical models to fit experimental data. The state-of-the-art in the domain implies extended use of specialised software, from simple freeware to complex, expensive ones; the paper proposes an investigation of the capabilities of some useful software, mainly applying the regression analysis of experimental data and some numerical examples and extends the discussion to dependability and performability

MODELING OF BIVARIATE DATA FOR DEPENDABILITY

For technical applications the dependability generally measures availability, reliability, maintainability, and connected activities like costs. The common effect of two or many properties on the same objects can be estimated with multivariate distributions using copula structures

RELIABILITY AND DESIGN OF EXPERIMENTS

The mechanical reliability uses many statistical tools to find the factors of influence and their levels inthe optimization of parameters on the basis of experimental data. Design of Experiments (DOE) techniquesenables designers to determine simultaneously the individual and interactive effects of many factors that couldaffect the output results in any design. The state-of-the-art in the domain implies extended use of software and abasic mathematical knowledge, mainly applying ANOVA and the regression analysis of experimental data

STATISTICAL METHODS AND THE RELIABILITY OF PRODUCTION EQUIPMENTS

The paper offers a synthesis of some important applications in the aria of analysis and processing of the reliability data of the production equipments documented by computer assisted specific statistical methods and regression model

A SHORT ANALYSIS OF THE OF THE SMARTPHONES RELIABILITY

A short analysis of some new results in the area of the reliability for smart mobile phones, the most used electronic devices, is of personal interest for every modern person. The strong competition induced by the globalization imposed necessary developments of the quality and reliability, fixed by ISO 9001-2015. The necessary huge availability of the mobile devices renders necessary new hardware and software efforts for reliability, especially for the first two competitors, Android and iOS. The paper presents mainly a short overview of a few recent statistical results, especially for the failure rates, and a comparison with older values (2011). An important growth of the reliability and availability is easy to detect, associated with the big efforts of the producers in testing these devices and huge development of applications

SOME STATISTICAL SOFTWARE APPLICATIONS FOR TAGUCHI METHODS

The paper details the variety of Taguchi methods, as important contribution to the quality improvement. The extended use of these methods imposes more and more complex calculi for the practical application and optimization. It should be necessary to benefit by the new software developments, assisted by the advanced statistical methods. The paper presents a few particular applications of some statistical software for the Taguchi methods as a quality enhancement insisting on the quality loss functions, the design of experiments and the new developments of statistical process control

DEPENDABILITY AND RELIABILITY OF MANUFACTURING SYSTEMS

Manufacturing systems are characterized by three fundamental properties: performance, cost, and dependability. The analysis of a system from the pure performance viewpoint tends to be optimistic since it ignores the failure/repair behaviour in the system. On the other hand, pure availability analysis tends to be too conservative since performance considerations are not taken into account. They improve product quality and reduce production losses. Dependability of a manufacturing system is the ability to deliver service (products) that can justifiably be trusted. Performance engineering addresses sustainability along with other factors like quality, reliability, maintainability and safety. The current paper introduces a framework for the fault analysis of production process, and the availability evaluation especially in the Flexible Manufacturing Systems (FMS’s). Generally, computing dependability measures of repairable systems with usual failure and repair processes is difficult, through either analytical or numerical methods. Mathematical models and application software for this kind of problems are in good stead. Recent advances in neural networks show that they can be used in applications that involve predictions, including the manufacturing

QUALITY LOSS FUNCTION FOR MACHINING PROCESS ACCURACY

The main goal of the paper is to propose new quality loss models for machining process accuracy in the classical case “zero the best”, MMF and Harris type. In addition a numerical example illustrates that the choose regression functions are directly linked with the quality loss of manufacturing process. The proposed models can be adapted for the “maximal the best” and “nominal the best” cases

FATIGUE CURVES FOR ALUMINIUM BRAZED AREAS

An important factor for the quality of joints is the brazed area. The fatigue check occupies a majorposition among many test procedures and methods, especially by the joining technologies. The results ofprocessing the fatigue data experiments for aluminium brazed probes are used to find the regression functionand the response surface methodolog

BLOCK DIAGRAM MODELS FOR CORRELATED STRUCTURES

The copula function offers new opportunities for advanced engineering design and can model correlated structures between random variables in reliability; in other words the dependence can describe time varying and nonlinear features of statistical links of marginal distributions. The paper proposes the study of reliability block diagrams by the analysis of the bridge model with links like serial-parallel, parallel-serial, based on total probability formula. The proposed reliability model built by copula functions is a new possible variant for statistical approach in the quality practice