The Management Oversight and Risk Tree (MORT) chart has been increasingly used and accepted as a method for analyzing a specific accident or, alternatively, evaluating an existing safety program for accident/incident potential. MORT has been designed for use as an investigative tool with which to focus upon the many factors contributing to an incident/accident. This chapter focuses on the explanation of the various MORT event tree symbols and their use/meaning. The primary symbols used for most analytical trees have been used in the this method event tree. this method investigation utilizes a color-coding system, as follows, to help identify those areas on the event tree where additional investigation or analysis is warranted. The objective of a this method analysis is to understand how specific “targets” were exposed to harm, damage, or unwanted change and to explain in terms of risk management.