Systems Thinking for Safety/Systems Thinking Methods
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The following are a selection of methods that adopt a systems thinking approach. Most of the methods are not specifically developed with safety in mind, but all can be used in a safety context. Each of the methods addresses several of the ten principles. All of the methods are in the public domain.
The systems methods require data collection via one or more fundamental methods, including:
- Observation of ordinary work with field experts
- Discussion with field experts
- Data and document review
- Survey methods
See Principles in Action for a brief description of the data collection methods above. For more detailed guidance, see Stanton et al (2013) and Wilson and Sharples (2014).
The methods below are listed in alphabetical order. For those who are new to the methods, a good place to start is with Systems Maps and Influence Diagrams. The various methods have different purposes and applications.
AcciMaps is a systems technique for accident analysis in complex sociotechnical systems, producing a multi-layered diagrams, spanning immediate causes to remote governmental or societal-level causal factors. It has has been used in a range of industries including aviation, rail transport, defence, oil and gas, and public health.
Activity Theory (sometimes called 'Cultural-Historical Activity Theory' or 'Activity Systems') aims at understanding everyday practice in the real world. It provides a method of describing, analyzing and understanding a phenomenon, finding patterns and making inferences across interactions.
Causal loop diagrams help to visualise how different variables in a system are interrelated. The diagram consists of a set of nodes and edges. Nodes represent the variables and edges are the links that represent positive or netative connections or a relation between the two variables.
Control charts are graphs used to study how system behaviour changes over time. Historical data are plotted in time order, with a central line for the average, an upper line for the upper control limit and a lower line for the lower control limit.
The Cynefin framework provides a typology of contexts that guides what sort of explanations or solutions might apply. It draws on research into complex adaptive systems theory, cognitive science, anthropology, and narrative patterns, as well as evolutionary psychology, to describe problems, situations, and systems.
The Functional Resonance Analysis Method or FRAM provides a way to describe outcomes using the idea of resonance arising from the variability of everyday performance.
Influence diagrams show interconnections between components of a system in the form of influence. They are often, but not always, a development of systems maps.
This SESAR Resilience Guidance Material for Safety Assessment (SRM) and Design is an on-going project to incorporate resilience engineering into safety assessment guidance in the context of the SESAR Safety Reference Material, and to formulate guidance for ATM concept design.
Soft systems methodology (SSM) is a systemic approach for tackling real-world problematic situations, where systems are seen as mental constructs used for human understanding. Rich pictures are a visual summaries of a complex situations involving human activity, comprising symbols, lines and sketches or "doodles" as perceived by the analyst(s). The approach encourages the creator to think deeply about a problem.
The Seven Samurai method proposes seven different systems and fifteen interactions between the systems that must be acknowledged and understood in systems engineering. By understanding these fifteen interactions, a better understanding the “whole picture” emerges. It is necessary to model the holistic situation including the seven systems and 15 interactions to ensure a solution is indeed the best way to solve the problem.
STAMP views accidents as resulting from inadequate control or enforcement of safety-related constraints on the design, development, and operation. Accidents occur when component failures, external disturbances, and/or dysfunctional interactions among system components are not adequately handled.
Systems maps describe the structure of a system under consideration from a particular perspective and for a particular purpose, within a boundary. Systems maps are a simple approach that provides a snapshot of the current situation (the system-as-found). The process of drawing and the resulting systems maps generates insights and understanding.
For more detailed guidance on the methods above, see the references for each method. Useful overviews of several methods are provided by Reynolds & Holwel (2010), Waring (1996) and Williams and Hummelbrunner (2010).
- Reynolds, M. & Holwel, S. (2010). Systems approaches to managing change: A practical guide. Open University Press.
- Stanton, N. A., Salmon, P.M., Rafferty, L.A., Walker, G.H., Baber, C. & Jenkins, D.P. (2013). Human factors methods: A practical guide for engineering and design (Second Edition). Ashgate.
- Open University (2014) Systems thinking and practice Part of an Open University course, freely available.
- Waring, A. (1996). Practical systems thinking. Thomson Learning.
- Williams, B. & Hummelbrunner, R. (2010). Systems concepts in action: A practitioner’s toolkit. Stanford University Press.
- Wilson, J.R. & Sharples, S. (2014). Evaluation of human work. Taylor and Francis.