Improving reliability in forensic engineering: the Delft approach

Based on established theories from literature and best practices of forensic investigations in aerospace engineering, civil engineering and biomechanical engineering, the Delft University of Technology has developed a Delft approach for forensic investigations. This integrated approach consists of three elements. First, because a product has a life cycle with various phases, it is of importance to consider these phases when a failure is investigated. Second, it is acknowledged that failure is a multifaceted phenomenon. Therefore, the 'Tree House of Failures' was developed, a taxonomy or categorisation of failure causes, which addresses main groups of causes of failure related to product, instruction and execution. Third, use of a standard investigative approach with the steps 'orientation', 'data collection', 'hypotheses generation', 'hypotheses testing', 'recommendations' and 'findings reporting' is advised. In the Delft approach, the 'ring of trustworthiness' is used to underline the mind-set that a forensic engineering investigator should have to assure the investigation's reliability and validity. The ring of trustworthiness states that an investigation should be objective, repeatable, verifiable, complete and correct. This paper presents the Delft approach for forensic investigations and explains how to use it to prevent several common pitfalls and biases that occur in various stages of a forensic engineering investigation. This approach aims to increase the reliability of forensic engineering investigations worldwide.