ABSTRACT
As automation increasingly shapes the operation of safety-critical systems, understanding human performance has become a cornerstone of resilient system design. This chapter introduces Safety-Critical Task Analysis (SCTA) using the Analysis of Pre-Accident Operator Actions (APOA) methodology. The task analysis and approach (methodology) are consistent with user-centred design methods, such as ISO 11064 and ISO 9241-210. SCTA provides a structured framework for identifying safety-critical tasks, analysing potential human errors, and designing systems that are inherently more tolerant to such errors. The chapter outlines a seven-step APOA process that integrates human factors into risk management – covering context establishment, task identification, task and error analysis, and improvement of human performance and error tolerance. It demonstrates how task analysis provides the analytical foundation for designing effective Human–Machine Interfaces (HMIs), developing procedures, managing workload, and supporting organizational learning. By aligning with user-centred design standards such as ISO 9241-210 and ISO 11064, SCTA enables iterative, participatory design and continuous improvement. APOA emphasizes qualitative understanding of why errors occur and how systems can be redesigned to prevent or recover from them. Through examples and practical tools, the chapter illustrates how SCTA operationalizes the Safety by Design philosophy – embedding human-centred thinking throughout the design of automation and remote operations.
