Formal risk assessment is a component of safety management relating to hazardous manual tasks (HMT). Systems thinking approaches are currently gaining interest for supporting safety management. Existing HMT risk assessment methods have been found to be limited in their ability to identify risks across the whole work system; however, systems thinking-based risk assessment (STBRA) methods were not designed for the HMT context and have not been tested in this area. The aim of this study was to compare the performance of four state-of-the-art STBRA methods: Net-HARMS, EAST-BL, FRAM and STPA to determine which would be most useful for identifying HMT risks. Each method was independently applied by one of four analysts to assess the risks associated with a hypothetical HMT system. The outcomes were assessed for alignment with a benchmark analysis. Using signal detection theory (SDT), overall STPA was found to be the best performing method having the highest hit rate, second lowest false alarm rate and highest Matthews Correlation Coefficient of the four methods.Practitioner summary: A comparison of four systems thinking risk assessment methods found that STPA had the highest level of agreement with the benchmark analysis and is the most suitable for practitioners to use to identify the risks associated with HMT systems.

Musculoskeletal disorders caused by hazardous manual handling (HMH) create a significant burden on society and detriment to the daily activities of the injured person. It is widely accepted in safety science that systems thinking is the most suitable approach to safety management, but its adoption in the HMH context remains unclear. The aim of this systematic review was to evaluate the extent to which existing observation-based HMH risk assessment methods align with systems thinking. The risks assessed by HMH methods and the risk controls identified based on the application of each method were assessed for alignment with a systems thinking framework. The results show that existing HMH risk assessment methods are not aligned with systems thinking and the risk controls identified from the application of HMH methods primarily reside with the task, worker and management. Areas were identified that would contribute to the application of systems thinking in HMH risk assessment; (1) developing safety practitioner knowledge of systems thinking; and (2) providing safety practitioners with new methods to support systems thinking in HMH risk assessment.