Forensic Study for Causes of Fall Using Fault Tree Analysis

A woman fell on a ramp in front of a pub and broke her ankle. She had had some drinks in the pub. Questions have been asked as who was to blame, the woman herself, her shoes, or the ramp. The writer introduces a fault tree model that can be used to solve the problem both qualitatively and quantitatively. The graphical model shows the interrelationships among the possible causes contributing to the fall. The qualitative and quantitative analyses produce the ranking of the minimal cut sets of causes that are most likely to contribute to the fall. Logical assessment and building codes support the qualitative analysis. The quantitative analysis requires the use of probability values. Some of these values are readily available, while others call for adequate judgment. A step-by-step process of solving the problem is presented in this paper.