Root Cause Analysis Tools
A fishbone diagram helps leaders identify multiple causes of a single problem. The diagram takes its name from its shape, which resembles the skeleton of a fish, as shown in the diagram below:
As shown in the diagram, the problem statement is placed at the “head” of the fish. Causes of this problem are grouped into four categories:
- People: Is there any staff behaviors or characteristics that are contributing to the problem?
- Process/policy: What procedures or policies contribute to the problem?
- Equipment: Is there any equipment, including supplies, that contribute to the problem?
- Environment: Does the immediate environment (i.e., the building or compound), or broader environment (i.e., the community, town, or nation) contribute to the problem?
As you identify factors that contribute to the problem, place them on the appropriate “fishbone.” For each factor that you identify, ask yourself, “What leads to that factor?” For example, in the diagram above, insufficient staffing was identified as an important factor in the poor quality of care. This is a people issue, and “Insufficient staffing in facilities” was placed on the people fishbone. Insufficient staffing can be linked to two other factors: inadequate education and poor role definition among health care workers. Both of these were added to the diagram.
Fishbone diagramming is useful for a number of reasons:
- Involves everyone in an open session: Using a chalkboard or other display to brainstorm allows everyone to contribute their ideas, no matter how big or small.
- Generates lots of diverse ideas quickly: Because there are many bones, there is room for many ideas.
- Helps group members understand and appreciate others’ perspectives: Some participants will be more focused on the environmental factors, while others will focus on factors related to people. The diagram makes room for all of these perspectives.
- Helps generate alternative approaches: Identifying multiple factors will lead to multiple possible solutions.
One drawback to the fishbone diagram is that this tool cannot tell you how important or common a particular issue is. To address this weakness, managers may wish to use a problem ranking matrix.
See video for an explanation of the Fishbone Diagram.
Once all of the possible causes are identified using a fishbone diagram, managers must determine which are the most important to address given limited resources. Problem ranking is an objective way to rank problems or root causes rather than simply picking the “favorite” option.
To prioritize root causes according to risk, we consider frequency (on the x-axis) and severity (on the y-axis). The factors that rank highest in terms of frequency and severity ought to be the priority problems.
Cost-benefit is a measure of how difficult or costly it is to fix the problem (on the y-axis), as compared to the level of benefit or improvement that is expected (on the x-axis).
Sometimes managers find it necessary to identify problems within larger processes or systems. The flow chart is a diagram that puts the process into pictures so that problems can be “seen.” A flow chart:
- Describes complex processes in manageable steps that can be improved
- Identifies breakdowns in the process
- Shows how one’s own actions influence “downstream” events
- Fosters a team that “owns” the whole process, as opposed to individuals focused only on fragments of the process
- Helps generate alternative approaches
A Pareto chart and histogram are useful tools for quantifying the frequency of common causes of the problem. By quantifying the frequency, managers can focus on the biggest issues first. The Pareto chart below shows reasons that inpatients do not receive required drugs:
Pareto charts include specific categories along the x-axis, as in the chart above. Histograms are like Pareto charts, but instead use continuous variables along the x-axis.
Histogram and Pareto analysis provides a useful representation of data that allows managers to prioritize. This analysis also helps generate alternative approaches and provides a tool for showing progress.