Root cause analysis (RCA) is a class of problem solving methods aimed at identifying the root causes of problems or events. The practice of RCA is predicated on the belief that problems are best solved by attempting to correct or eliminate root causes, as opposed to merely addressing the immediately obvious symptoms. By directing corrective measures at root causes, it is hoped that the likelihood of problem recurrence will be minimized. However, it is recognized that complete prevention of recurrence by a single intervention is not always possible. Thus, RCA is often considered to be an iterative process, and is frequently viewed as a tool of continuous improvement. Problem solving forms part of thinking. ... A root cause is a cause that is at a root of an effect. ... Continuous improvement is a phrase suggesting that a process or product should always get better as knowledge about it and experience with it accumulates over time. ...

Root cause analysis is not a single, sharply-defined methodology; there are many different tools, processes, and philosophies of RCA in existence. However, most of these can be classed into five, very-broadly defined "schools" that are named here by their basic fields of origin: safety-based, production-based, process-based, failure-based, and systems-based.

• 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.

Despite the seeming disparity in purpose and definition among the various schools of root cause analysis, there are some general principles that could be considered as universal. Similarly, it is possible to define a general process for performing RCA. Accident Analysis is a form of Behavioural Systems analysis. ... It has been suggested that Worker safety and health be merged into this article or section. ... In engineering and manufacturing, quality control and quality engineering are involved in developing systems to ensure products or services are designed and produced to meet or exceed customer requirements. ... Manufacturing , a branch of industry, is the application of tools and a processing medium to the transformation of raw materials into finished goods for sale. ... A business process is a set of linked activities that create value by transforming an input into a more valuable output. ... Failure analysis is the process of determining the cause of failure, collecting and analyzing data, and developing conclusions to eliminate the failure mechanism causing specific device or system failures. ... Engineering is the design, analysis, and/or construction of works for practical purposes. ... Maintenance, Repair and Operations or Maintenance, Repair and Overhaul (MRO), is fixing any sort of mechanical or electrical device should it get out of order or broken (repair) as well as performing the routine actions which keep the device in working order (maintenance) or prevent trouble from arising (preventive maintenance). ... Change is a fact of life. ... Risk management is the process of measuring, or assessing, risk and developing strategies to manage it. ... This article or section does not adequately cite its references or sources. ...

General principles of root cause analysis

1. Aiming corrective measures at root causes is more effective than merely treating the symptoms of a problem.
2. To be effective, RCA must be performed systematically, and conclusions must be backed up by evidence.
3. There is usually more than one root cause for any given problem.

General process for performing root cause analysis

1. Define the problem.
2. Gather data/evidence.
3. Identify issues that contributed to the problem.
4. Find root causes.
5. Develop solution recommendations.
6. Implement the solutions.

Root Cause Analysis Tools

1. 5 Whys
2. Barrier Analysis
3. Change Analysis
4. Causal Factor Tree Analysis
5. Failure mode and effects analysis
6. Fish-Bone Diagram or Ishikawa diagram
7. Pareto Analysis
8. Fault Tree Analysis