Monetary and quality-feature-based quantification of failure risks in existing process chains
Common approaches for the analysis and optimisation of processes, such as the Statistical Process Control (SPC) or the Failure Mode and Effects Analysis (FMEA), do not support a systematic and reproducible priorisation of quantified, quality-feature-based failure risks. For example, process capability indices can only be interpreted from a process-specific and technical perspective but do not imply any information that describe the importance for the company. In contrast, the Risk Priority Number (RPN) includes a factor that describes the importance. However, this factor can be considered as subjective and, therefore, it can affect the reproducibility. Moreover, common approaches do not give any instruction how to aggregate quantifying values of several risks. This complicates a comparison of existing process chains based on their quantified failure risks. To overcome these deficiencies, a new method is introduced in this paper. It enables a monetary quantification of failure risks related to selected quality features. This includes the systematic design of quality-feature-based cost functions that quantify expected failure costs as well as so-called near misses. Furthermore, it supports the aggregation of risk-quantifying values. This enables a simple risk-related comparison of whole existing process chains.