The oil and gas construction industry experiences a high rate of unnecessary work-related fatalities. The International Association of Oil and Gas Producers (IOGP) reported 54 fatalities in 40 fatal incidents in 2015. When assessing this against the use of IOGP Life-Saving Rules (LSRs), which contractors are required to adopt, the IOGP found that of the 40 fatal incident descriptions in 2015, at least 73% related to the IOGP LSRs. A program to apply a critical control management (CCM), or safety cased, approach to fatal hazards was trialled on construction sites in Australia and South Africa ranging from large power station constructions to offshore hook-up and commissioning to brownfields maintenance. The results demonstrated a step change in the safety performance occurred on projects where the CCM program was implemented. These projects have each demonstrated a significant improvement in recordable injuries, increases in hazard reporting and awareness, and almost complete elimination of high-potential incidents. Further investigation of the reasons for these results is the subject of a PhD project and includes: (1) understanding how the CCM program improves hazard awareness and decision making of frontline supervisors; (2) determining the effects CCM has on the safety climate of the organisation as detailed focus is applied on the effectiveness of controls that drive leadership decisions; and (3) investigating how CCM improves leadership at all levels of the organisation due to better information that allows tangible action to be taken to improve control effectiveness. This paper describes the progress of CCM program development, details present results and lessons learned, and provides a context for how CCM programs can be implemented in other organisations.