The Operational Demand Evaluation Checklist (ODEC) of workload for railway signalling

This paper is concerned with the interpretation and assessment of mental workload, and in particular assessment of the load imposed by the work system. It highlights a framework created to direct the development of workload assessment tools capable of assessing the dimensions most relevant to the population being studied, in our case railway signallers. A tool to capture the operational demands on the rail signaller was required to evaluate the load from the system they operated. This paper justifies the need for, and describes the development of, the Operational Demand Evaluation Checklist (ODEC), using techniques like repertory grid with active signallers. The practical experience of the development, evaluation, live use and validation of ODEC is discussed and the paper concludes by suggesting that the approach could be adopted to interpret the concept of workload in other work domains.