Reliability monitoring, feedback and improvement systems:their application in the machine tool industry

Abstract

This thesis provides an overview and synthesis of the results of a major study on reliability management practices in the machine tool industry. The investigation was undertaken to provide an information base, at an operational level, of practical use for reliability management development by key decision makers in the fields of design, manufacturing, service and supplier development. To make sense of the problems and practices found in machine tool enterprises, an integrated approach was adopted. The study addressed the principal underlying variables: the design, manufacture and supplier development aspects of reliability, the use of field performance data in design modification and improvement, and the application of reliability-based methods for reliability appraisal. The core of the project consists of longitudinal studies using methods of ‘action research.’ In addition to this, a survey was conducted. The combination of both these approaches provided a consistent and representative presentation of the reliability management practices in the industry. Three points can be made concerning the findings on the most significant problems faced by manufacturers. First, it was clear that manufacturers pay insufficient attention to reliability related issues at all stages of the product design and development process. Second, little systematic and consistent use is made of field failure data in the area of reliability improvement. Companies showed a lack of interest in measuring important field reliability variables, except when major problems arise. Third, there was a marked absence of evidence that reliability-based techniques had been used among the systems for design analysis and engineering decision making. These problems illustrate the areas of deficiency regarding reliability management and determine ways in which these can be overcome. The deficiencies identified in the approaches to the management of product reliability were addressed by the development of a generic methodology for improving machine tool reliability. This consists of a set of guidelines and techniques, which in totality provides the basis for improving the reliability management process. It is intended primarily for the machine tool industry but will have potential applications elsewhere.