Conformability analysis for the control of quality costs in electronic systems

The variations embodied in the production of electronic systems can cause that system to fail to conform to its specification with respect to Critical to Quality features. As a consequence of such failures the system manufacture may incur significant quality costs ranging from simple warranty returns up to legal liabilities. It can be difficult to determine both the probability that a system will fail to meet its specification and estimate the associated cost of failure. This thesis presents the Electronic Conformability Analysis (eCA) technique a novel methodology and supporting tool set for the assessment and control of quality costs associated with electronic systems. The technique addresses the three main elements of production affecting quality costs associated with electronic systems which are functionality, manufacturability and testability. Electronic Conformability Analysis combines statistical performance exploration with process capability indices, a modified form of Failure Modes and Effects Analysis and a cost mapping procedure. The technique allows the quality costs associated with design and manufacture induced failures to be assessed and the effectiveness of test strategies in reducing these costs to be determined. Through this analysis of costs the technique allows the potential trade-offs between these costs and those associated with design and process modifications to be explored. In support of the Electronic Conformability Analysis technique a number of new analysis tools have been developed. These tools enable the methodology to cope with the specific difficulties associated with the analysis of electronic systems. The technique has been applied to a number of analogue and mixed signal, safety critical circuits from automotive systems. These case studies have included several different levels of system complexity ranging from relatively simple transistor circuits to highly complex mechatronic systems. These case studies have shown that the technique is effective in a commercial design and manufacturing environment