Root cause analysis (RCA) overview

Root cause analysis (RCA) is a method of problem solving by attempting to identify and correct the root causes of events, as opposed to simply addressing their symptoms. Focusing correction on root causes has the goal of preventing problem recurrence. Complete prevention of recurrence by one corrective action is not always possible. Conversely, there may be several effective measures (methods) that address the root causes of a problem. Thus, RCA is an iterative process and a tool of continuous improvement.

RCA is typically used as a reactive method of identifying event(s) causes, revealing problems and solving them. Analysis is done after an event has occurred.

RCA is not a single, sharply defined methodology; there are many different tools, processes, and philosophies for performing it. However, several very-broadly defined approaches or schools can be identified by their basic approach or field of origin:

• Safety-based RCA descends from the fields of accident analysis and occupational safety and health.
• Production-based RCA has its origins in the field of quality control for industrial manufacturing.
• Process-based RCA is basically a follow-on to production-based RCA, but with a scope that has been expanded to include business processes.
• Failure-based RCA is rooted in the practice of failure analysis as employed in engineering and maintenance.
• Systems-based RCA has emerged as an amalgamation of the preceding schools, along with ideas taken from fields such as change management, risk management, and systems analysis.

Problems with root cause analysis

Despite the different approaches among the various schools of root cause analysis, there are some common principles.

General principles of RCA

1. The primary aim of root cause analysis is to identify the factors that resulted in the nature, the magnitude, the location, and the timing of the harmful outcomes (consequences) of one or more past events in order to identify what behaviours, actions, inactions, or conditions need to be changed to prevent recurrence of similar harmful outcomes and to identify the lessons to be learned to promote the achievement of better consequences. (Successis defined as the near-certain prevention of recurrence.)
2. To be effective, root cause analysis must be performed systematically, usually as part of an investigation, with conclusions and root causes that are identified backed up by documented evidence. Usually a team effort is required.
3. There may be more than one root cause for an event or a problem, the difficult part is demonstrating the persistence and sustaining the effort required to determine them.
4. The purpose of identifying all solutions to a problem is to prevent recurrence at lowest cost in the simplest way. If there are alternatives that are equally effective, then the simplest or lowest cost approach is preferred.
5. Root causes identified depend on the way in which the problem or event is defined. Effective problem statements and event descriptions (as failures, for example) are helpful, or even required.
6. To be effective, the analysis should establish a sequence of events or timeline to understand the relationships between contributory (causal) factors, root cause(s) and the defined problem or event to prevent in the future.
7. Root cause analysis can help transform a reactive culture (that reacts to problems) into a forward-looking culture that solves problems before they occur or escalate. More importantly, it reduces the frequency of problems occurring over time within the environment where the root cause analysis process is used.
8. Root cause analysis is a threat to many cultures and environments. Threats to cultures often meet with resistance. There may be other forms of management support required to achieve root cause analysis effectiveness and success. For example, a non-punitive policy toward problem identifiers may be required.

RCA-based Corrective Action

• RCA (in steps 3, 4 and 5) forms the most critical part of successful corrective action, because it directs the corrective action at the true root cause of the problem. Knowing the root cause is secondary to the goal of prevention, but without knowing the root cause, it is not possible to determine what an effective corrective action for the defined problem would be.
• Define the problem or describe the event factually. Include the qualitative and quantitative attributes (properties) of the harmful outcomes. This usually includes specifying the natures, the magnitudes, the locations, and the timing of events.
• Gather data and evidence, classifying it along a timeline of events to the final failure or crisis. For every behavior, condition, action, and inaction specify in the timeline what should have been done when it differs from what was done.
• Ask why and identify the causes associated with each step in the sequence towards the defined problem or event. Why is taken to mean What were the factors that directly resulted in the effect?
• Classify causes into causal factors that relate to an event in the sequence and root causes, that if eliminated, can be agreed to have interrupted that step of the sequence chain.
• Identify all other harmful factors that have equal or better claim to be called root causes. If there are multiple root causes, which is often the case, reveal those clearly for later optimum selection.
• Identify corrective action(s) that will with certainty prevent recurrence of each harmful effect, including outcomes and factors. Check that each corrective action would, if pre-implemented before the event, have reduced or prevented specific harmful effects.
• Implement the recommended root cause correction(s).
• Ensure effectiveness by observing the implemented recommendation solutions.
• Identify other methodologies for problem solving and problem avoidance that may be useful.
• Identify and address the other instances of each harmful outcome and harmful factor.

Variation in performance can produce unexpected and undesired adverse outcomes, including the occurrence of, or risk of, a sentinel event. Root cause analysis is a process for identifying the basic or causal factors that underlie such variation and focuses primarily on systems and processes, not individual performance. To be successful, it must not assign blame. Particular attention is paid to failed (and successful) defenses and recoveries for the patient, since adverse events require the formal instigation of defenses (for example, a medication is discontinued), whereas near misses involve built-in defenses (for example, automatic compensation through stand-by equipment). Improvements in the delivery of care are devised and implemented to prevent the adverse outcome from recurring, or at least to reduce the possibility of its recurrence and to ameliorate its consequences. The lessons learned are communicated to all hospital staff as a way to improve patient safety.

Related Resources

1. Joint Commission Resources, Inc. Root Cause Analysis in Health Care: Tools and Techniques. 2nd ed Joint Commission on Accreditation of Healthcare Organizations, Illinois. 2003 www.amazon.com
2. Institute of Medicine. Patient Safety: Achieving a new standard for care. Quality Chasm Series, National Academies Press, Washington, DC. 2004 www.ncvhs.hhs.gov
3. Institute of Medicine. Crossing the Quality Chasm: A New Health System for the 21st Century National Academies Press, Washington, DC. 2001 BMJ Clinical Research
4. Institute of Medicine. To Err is Human: Building A Safer Health System National Academies Press, Washington, DC. 2000 www.ihi.edu/Redoutvrd/
5. NHS England and NHS Improvement South West. Publications: Investigation Reports www.england.nhs.uk/south/
6. ​​National Patient Safety Foundation. ​ RCA2: Improving Root Cause Analyses and Actions to Prevent Harm. Boston, MA: National Patient Safety Foundation; 2015. www.ihi.org
7. C.W. Johnson, Failure in Safety-Critical Systems: A Handbook of Accident and Incident Reporting. University of Glasgow Press, Glasgow, Scotland, October 2003. www.dcs.gla.ac.uk/~johnson/book/