Five Whys, Fishbone, and Fault Tree Analysis answer different investigation questions. This executive comparison shows when each method fits, where each can mislead, and how leaders can connect findings to verified controls after a serious incident.
Dr. Thomas Krause argues that incident investigations often fail before the interview, because leaders begin with employee fault instead of testing the conditions that shaped the decision.
The June 21, 2019 Philadelphia Energy Solutions refinery explosion was not only a failure of refinery equipment and process-safety governance. The U.S. Chemical Safety and Hazard Investigation Board investigation exposed how incomplete records, weak integrity decisions, and unclear accountability allowed a serious risk to remain present until the system failed catastrophically.
A safety investigation is only decision-ready when its evidence connects the event to the conditions, control, and action that must change. This explainer presents four links for building that chain.
The Piper Alpha disaster is often remembered as an offshore fire, but the deeper case is about information that did not travel with the work. This narrative case study examines how permit handover, isolation status, emergency communication, and barrier ownership interacted before the 1988 catastrophe, then turns the lessons into a practical test for high-risk operations.
The Farmington No. 9 explosion killed 78 miners in 1968 and helped trigger the Federal Coal Mine Health and Safety Act of 1969. Its enduring lesson is not only technical control. It is how leaders convert catastrophic evidence into decisions that remain visible after the memorials, hearings, and headlines fade.
Near-miss classification is useful only when it distinguishes a condition, an exposure, a failed barrier, and a consequence. This glossary shows how each state changes the response.
The 1976 Seveso chemical release shows why major-hazard responsibility cannot stop at the facility boundary. This case study follows the governance reset that connected process safety, emergency planning, land use, public information, and executive ownership.