Task Analysis¶

Status: emerging
Last updated: 2026-05-31
Sources: 9781119636113.Ch13.Pdf
Tags: [task-analysis, hierarchical-task-analysis, functional-analysis, cognitive-task-analysis, work-analysis, methods]

Summary¶

Task analysis is the structured description of work to support its design, management, and improvement (Hollnagel, 2021). The chapter argues that classical decomposition-based methods worked when work was simple and observable, but the growing dependence on technological artefacts has made work less directly visible, requiring a shift from structural to functional analysis. It distinguishes bottom-up, top-down (goals-means), and functional approaches, with the Functional Resonance Analysis Method (FRAM) offered as a functional alternative.

Body¶

Context¶

Hollnagel (2021), in his handbook chapter on the changing nature of task analysis, examines how work should be described to support its design, management, and improvement. He argues that classical decomposition-based methods worked when work was simple and observable, but that growing dependence on technological artefacts has made work less visible, requiring a shift from structural to functional analysis. Within this knowledge base the article is the work-description method that feeds the human-centred process: it precedes and informs the requirements work in User Requirements Methods, supports the system-level framing in Human Systems Integration and the structuring of work in Job And Team Design, and its functional, resilience-oriented stance connects to the systemic view of failure in Human Error And Reliability.

Key Points¶

Task analysis exists because humans have always depended on tools and artefacts to achieve their purposes, and understanding that dependence is necessary to design and manage work. Hollnagel traces the need for task analysis to two historical pushes: productivity, and concern over the inconsistency of the human factor (PDF pp. 2–3, orig. pp. 359–360). For a long time work and its surroundings were simple enough that analyses could be based directly on observing how work was done, which also made work relatively easy to manage. This observability is the assumption Hollnagel argues has eroded (PDF p. 6, orig. p. 363).

The changing nature of work undermines classical decomposition. Decomposition worked because work and organisations were simple enough to follow what happened and why, but the increasing inclusion of and dependence on technological artefacts made work less visible. When work cannot be directly observed, analyses based on observation of actions lose their footing, which motivates the move from structural to functional analysis (PDF p. 6, orig. p. 363).

Hollnagel distinguishes three analytic strategies. Bottom-up task analysis derives from classical sequential and hierarchical studies of observable actions. Top-down or goals-means task analysis starts from the overall goal and decomposes it into sub-goals and means, with the General Problem Solver of Newell and Simon (1961, cited in Hollnagel, 2021) as the classic illustration. Functional analysis starts from neither the goal nor the observable actions but from the functions necessary to accomplish something, described as functions rather than tasks (PDF pp. 7–8, orig. pp. 364–365).

The Functional Resonance Analysis Method is the functional exemplar. FRAM (Hollnagel, 2012) produces a functional model of how something can be or has been done, describing functions in terms of what they require and produce rather than as a fixed sequence of tasks. This suits work where the path between intention and outcome is variable and not directly observable (PDF p. 8, orig. p. 365).

Conclusion¶

Hollnagel (2021) concludes that as work becomes less observable, task analysis must move from describing structures of actions to describing functions and their couplings. FRAM exemplifies this functional alternative, which he argues better matches the variable, technology-mediated reality of modern sociotechnical work than bottom-up or goals-means decomposition.

References¶

Hollnagel, E. (2021) 'The Changing Nature of Task Analysis', in Salvendy, G. & Karwowski, W. (eds.) Handbook of Human Factors and Ergonomics. 5th edn. Hoboken, NJ: John Wiley & Sons. hollnagel2021taskanalysis

Newell, A. & Simon, H. A. (1961). GPS: A program that simulates human problem-solving. In Proceedings of a Conference on Learning Automata. Technische Hochschule, Karlsruhe, Germany, April 11–14. To be validated.

Open Questions¶

When does observability of work break down enough that bottom-up task analysis should be abandoned for functional analysis?
How does FRAM's functional modelling integrate with traditional hierarchical task analysis in mixed sociotechnical systems?