Practical Risk Analysis — As a Tool for Minimizing Plastic Product Failures

Abstract

This chapter describes some of the practical and simplified approaches, and how they can be effectively used to design and minimize the risk of plastic product failures. Each of the risk analysis technique has its own advantages and shortcomings. The quantitative analysis techniques such as Fault Tree Analysis and Event Tree analysis can yield definitive results but usually require enormous effort in model development, data collection, and quantification of uncertainties. The qualitative (or semi-quantitative) risk analysis tools such as Preliminary Hazards Analysis (PHA) or Failure Mode and Effects Analysis (FMEA) yield quick results that are not quantitative, but can be cost-effectively used to prioritize the relative risks. If a deductive or “top down” approach is used, the FMEA process can be completed within a reasonable time frame. Qualitative indices can also be used to reduce the burden of being precise or quantitative while maintaining the intended resolution of the FMEA. Depending on the nature of the information in this phase, a relative scale for the likelihood of occurrence and detectability indices have been developed, from which values are objectively assigned to individual scenarios. These indices are constructed to be broad brush, rather than detailed, and are usually qualitative rather than quantitative.