RCA Scope Paradox
Root cause analysis faces a dilemma: a narrow scope is quick and resource-efficient but may miss root causes, while a broad scope is thorough but costly and may lead to fewer actions being implemented.
THE IDEA
A Paradox at the Heart of an RCA or Inquiry Scope
So, if you reflect on the depth and breadth of an inquiry or RCA and the actions you might take afterward, you can face the following dilemma:
- If you know you have a limit on the resources for an RCA and remediation actions, you can focus the scope of any RCA work and do it quite quickly, but you may miss other important improvement opportunities;
- If you have an ambitious scope, this should maximise the chances that all the principal root causes will be uncovered so that numerous improvement actions will be proposed.4 But this (i) increases the time, effort and cost required, and (ii) increases the chances that a more comprehensive set of actions may not be taken up.
The more significant the issue that is being looked at, the more this will suggest you should have a ‘gold‐plated’ RCA or inquiry; and this is why air crash investigations (e.g. by the US National Transportation Safety Board) and public inquiries into major disasters can be very high quality, with a sufficiently broad scope to get at crucial causal factors, wherever they are located. However, if resources are constrained or there are other priorities or there are political dynamics in play, it is not unusual to be disappointed with inquiry scopes, and getting proposed actions agreed and implemented.
When to use it
Deciding how thoroughly to investigate a recurring issue in a manufacturing line with limited maintenance staff.
Planning a post-mortem for a major software outage where the cost of downtime is high but development resources are scarce.
Setting the scope of a safety review after a near-miss in a hospital, balancing thoroughness with the need to keep operations running.
Determining the depth of a project post-review when the project failed partially but the team is already moving to the next initiative.
FROM THEORY TO EVERYDAY LIFE
In practice
Air Crash Investigations
The source cites US National Transportation Safety Board investigations as examples of broad inquiries that can examine causal factors across organizational boundaries. Their scope requires resources, and implementing recommendations remains a separate challenge.
Typical Workplace Incident
A minor injury in a factory: a narrow, quick RCA might identify immediate causes (e.g., missing guard) but omit deeper issues like inadequate training or pressure to work faster, while a broad RCA could expose systemic problems but risk being too costly or causing action fatigue.
A MOMENT TO REFLECT
Put it to work.
Think of a recent problem you investigated. How did the scope you chose affect what you found and what actions were taken?
When deciding the scope of an inquiry, what trade-offs are you most willing to accept between completeness and feasibility?
In your organization, what factors typically constrain the depth of root cause analyses? How might those be addressed?
CONTINUE THE CONVERSATION
Source texts
- Beyond the Five Whys Root Cause Analysis and Systems Thinking (James C. Paterson)