Systems Thinking for Safety/Principle 6. Interactions and Flows
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Work progresses in flows of inter-related and interacting activities
Understand system performance in the context of the flows of activities and functions, as well as the interactions that comprise these flows
When looking at an organisation, we have a tendency to see it in terms of the organisational structure. This is how management normally works – managing resource in separate entities such as divisions, departments and units. This top-down perspective is problematic from an outside-in and end-to-end perspective – and this is the perspective of the customer. By managing individual functions, parts of the system compete. Goal conflicts are introduced and functions achieve their own goals at the expense of the whole, and to the expense of the customer. This ‘sub-optimisation’ is made worse when measurements are attached to functions or discrete activities, instead of focusing on system purpose.
When looking at an organisation as a system, it is necessary to see the flows of work from end to end through the system, and the interactions that make up these flows. The flow of work is not always obvious when we are only involved in a small part or a particular activity. But there is always flow. Flow in ATM is triggered and pulled by demand from external customers (e.g. airline pilots and dispatchers) and internal customers (within an ANSP, e.g. controllers, technicians, AIS, meteo staff). From a systems perspective, the task of management is to manage end-to-end flows, not functions. This means designing work according to purpose – to satisfy customer demands.
Acting on flow is a key system lever; it has a fundamental effect on performance. By studying, designing and managing flow, production and safety improvements emerge. Improving flow starts with designing against demand (Seddon, 2005). The variety and variability of demand needs to be understood. Improving flow also means paying attention to resources and constraints; when these are inadequate, they can be a particular problem for flow. Typical design-related flow blockers include poor interaction design (equipment and information), and unnecessary, overly complex or restrictive procedures. Designing these out requires a systems thinking approach. Bureaucracy of all kinds hinders flow, especially when staff need to cut across organisational boundaries to get work done. When this happens, there are delays and the immediacy of need diminishes. For operational staff, the pressure builds up as time goes on.
To improve flow, you need measures of the nature and variability of demand and flow. The measures will give an idea of the capability of the system to handle demands and the predictability of work. This measurement of flow needs to be end-to-end. For each flow, you need data about achievement of purpose in customer terms. These measures need to be taken with the people who do the work – the field experts. They can help to understand the nature and predictability of flow. Measurement and analyses which dislocate decisions and actions from the demand, flow of work and context cannot explain performance or help to improve it. As noted by Seddon “To manage clean flow, workers need to have the expertise required by the nature of demand. They also need to be in control of their work, rather than being controlled by managers with measures of output, standards, activity and the like” (2005, p. 59).
Viewing the system as a whole, emerging patterns of activity become evident. These patterns, along with flows, can be seen using systems methods. The system interactions that make up these flows and patterns concern the integration of the human, technical, information, social, political, economic and organisational components of the system ( Wilson, 2013). The nature of interactions, flows and patterns, along with purpose, characterise the system. There are many methods in human factors/ergonomics for studying interactions involving humans within systems (e.g. Stanton et al, 2013; Williams and Hummelbrunner, 2010; Wilson and Sharples, 2014). Considering interactions in the context of the flow of work, within the wider system, and from the viewpoints of those involved will help to improve the system, both for safety and productivity.
- Understand and measure flow. Investigate the flow of work from end to end through the system. Map the variability of flows and anything that obstructs, disrupts, delays or diverts the flow of work (e.g. preconditions not met, constraints, or unusual events). Consider how flow is measured, or could be measured, and the role of field experts in measuring and acting on flow.
- Analyse and synthesise interactions. Consider how to model past, present or future system interactions between human, technical, information, social, political, economic and organisational elements. Think about what systems methods to use and how to involve relevant field experts to help understand the interactions.
View from the field
Dr Anthony Smoker Manager Operational Safety Strategy (NERL), NATS; Former Air Traffic Controller; Graduate Tutor, Human Factors & System Safety, Lund University
“Work can be described as the patterns of activity that characterise our daily working lives. We can see these patterns of activity as interactions with technology, procedures and equipment, situated in a wider system. The wider system is characterised by work flows that change as demand changes. Seen from a systems view, the patterns of activity can lead to new or infrequent interactions which the system may not support. New goal conflicts may be introduced that influence work with new priorities and new interactions, which technical systems (e.g. telephone or data processing) may not support. Procedures may not exist to support the new flows or interactions, and so flexibility is required to achieve a desirable outcome. Safe and efficient operation comes about by our adaptation to the changing patterns of flows and interactions. Understanding these – with the field experts – gives us the foresight to be able to manage operations intelligently.”
Source: Systems Thinking for Safety: Ten Principles. A White Paper. Moving towards Safety-II, EUROCONTROL, 2014.
The following Systems Thinking Learning Cards: Moving towards Safety-II can be used in workshops, to discuss the principles and interactions between them for specific systems, situations or cases.