Root cause analysis (RCA) is a class of problem solving Problem solving is a mental process and is part of the larger problem process that includes problem finding and problem shaping methods aimed at identifying the root causes A root cause is an initiating cause of a causal chain which leads to an outcome or effect of interest. Commonly, root cause is used to describe the depth in the causal chain where an intervention could reasonably be implemented to change performance and prevent an undesirable outcome 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 Some see it as a meta process for most management systems . Deming saw it as part of the 'system' whereby feedback from the process and customer were evaluated against organisational goals. The fact that it can be called a management process does not mean that it needs to be executed by 'management' merely that it makes decisions about the.
RCA, initially is a reactive method of problem detection and solving. This means that the analysis is done after an event has occurred. By gaining expertise in RCA it becomes a pro-active method. This means that RCA is able to forecast the possibility of an event even before it could occur.
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 Accident Analysis is carried out in order to determine the cause or causes of an accident or series of accidents so as prevent further incidents of a similar kind. It is also known as accident investigation. It may be performed by a range of experts, including forensic scientists, forensic engineers or health and safety advisers and occupational safety and health Occupational safety and health is a cross-disciplinary area concerned with protecting the safety, health and welfare of people engaged in work or employment. The goal of all occupational safety and health programs is to foster a safe work environment. As a secondary effect, it may also protect co-workers, family members, employers, customers,.
- Production-based RCA has its origins in the field of quality control In engineering and manufacturing, quality control and quality engineering are used in developing systems to ensure products or services are designed and produced to meet or exceed customer requirements for industrial manufacturing Manufacturing is the use of machines, tools and labor to make things for use or sale. The term may refer to a range of human activity, from handicraft to high tech, but is most commonly applied to industrial production, in which raw materials are transformed into finished goods on a large scale. Such finished goods may be used for 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 A business process or business method is a collection of related, structured activities or tasks that produce a specific service or product for a particular customer or customers. It often can be visualized with a flowchart as a sequence of activities.
- Failure-based RCA is rooted in the practice of failure analysis Failure analysis is the process of collecting and analyzing data to determine the cause of a failure and how to prevent it from recurring. It is an important discipline in many branches of manufacturing industry, such as the electronics industry, where it is a vital tool used in the development of new products and for the improvement of existing as employed in engineering Engineering is the discipline, art and profession of acquiring and applying technical, scientific and mathematical knowledge to design and implement materials, structures, machines, devices, systems, and processes that safely realize a desired objective or inventions. The American Engineers' Council for Professional Development has defined and maintenance Maintenance, repair and operations is fixing any sort of mechanical or electrical device should it become out of order or broken as well as performing the routine actions which keep the device in working order (known as scheduled maintenance) or prevent trouble from arising (preventive maintenance). MRO may be defined as, "All actions which.
- Systems-based RCA has emerged as an amalgamation of the preceding schools, along with ideas taken from fields such as change management Change management is the process during which the changes of a system are implemented in a controlled manner by following a pre-defined framework/model with, to some extent, reasonable modifications, risk management Risk Management is the identification, assessment, and prioritization of risks followed by coordinated and economical application of resources to minimize, monitor, and control the probability and/or impact of unfortunate events. Risks can come from uncertainty in financial markets, project failures, legal liabilities, credit risk, accidents,, and systems analysis Systems analysis is the interdisciplinary part of Science, dealing with analysis of sets of interacting entities, the systems, often prior to their automation as computer systems, and the interactions within those systems. This field is closely related to operations research. It is also "an explicit formal inquiry carried out to help someone,.
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.
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General principles of root cause analysis
- Aiming performance improvement measures at root causes is more effective than merely treating the symptoms of a problem.
- To be effective, RCA must be performed systematically, with conclusions and causes backed up by documented evidence.
- There is usually more than one potential root cause for any given problem.
- To be effective the analysis must establish all known causal relationships between the root cause(s) and the defined problem.
- Root cause analysis transforms an old culture that reacts to problems to a new culture that solves problems before they escalate, creating a variability reduction and risk avoidance mindset.
General process for performing and documenting an RCA-based Corrective Action
Notice that RCA (in steps 3, 4 and 5) forms the most critical part of successful corrective action, because it directs the corrective action at the root of the problem. That is to say, it is effective solutions we seek, not root causes. Root causes are secondary to the goal of prevention, and are only revealed after we decide which solutions to implement.
- Define the problem.
- Gather data/evidence.
- Ask why and identify the causal relationships associated with the defined problem.
- Identify which causes if removed or changed will prevent recurrence.
- Identify effective solutions that prevent recurrence, are within your control, meet your goals and objectives and do not cause other problems.
- Implement the recommendations.
- Observe the recommended solutions to ensure effectiveness.
- Variability Reduction methodology for problem solving and problem avoidance.
Root cause analysis techniques
- Current Reality Tree Current reality tree refers to the repair activity for ships. An initial inquiry check for availability of dock space and repair berth, vessel draft restriction, repair scope compared with yard work load estimating and forward any queries A method developed by Eliahu M. Goldratt in his Theory of Constraints that guides an investigator to identify and relate all root causes using a cause-effect tree whose elements are bound by rules of logic (Categories of Legitimate Reservation). The CRT begins with a brief list of the undesirables things we see around us, and then guides us towards one or more root causes. This method is particularly powerful when the system is complex, there is no obvious link between the observed undesirable things, and a deep understanding of the root cause(s) is desired.
- Behavior Justification A program designed to teach critical thinking skills for problem solving. The program teaches that "cause and effect" is a relative term, meaning that depending from what direction through time one is observing a fact determins its input "cause" or "effect." This means that each fact is actually both except for the root causes. A process is used to construct a Gestalt model using the facts of an event. This model mimics the human thought process for organizing and connecting information that is causally related. The model is a solution path from the problem to the causes. The application of this program induces culture change for improvement.
- Cause and effect analysis A technique that organizes the analyst's knowledge into a cause and effect chain. For every effect, there is a cause. There is a fairly long chain of relationship between the cause and its effect. In theory, if the lowest cause on the chain is removed, the problem will not re-appear. Root Cause is a variability reduction methodology for problem solving and problem avoidance. Root cause mindset transforms an old culture that reacts to problems to a new culture that solves problems before they escalate, creating a cost effective variability reduction and risk avoidance mindset.
- 5 Whys The 5 Whys is a question-asking method used to explore the cause/effect relationships underlying a particular problem. Ultimately, the goal of applying the 5 Whys method is to determine a root cause of a defect or problem
- Kepner-Tregoe Kepner-Tregoe's trademark technique, Rational Process, which is commonly referred to as the 'KT Process', is the creation of structured, systematic processes which are used to maximise the critical thinking skills of key stakeholders in a particular situation, problem , decision or opportunity Problem Analysis - a root cause analysis process developed in 1958, which provides a fact-based approach to systematically rule out possible causes and identify the true cause
- Failure mode and effects analysis A failure modes and effects analysis is a procedure for analysis of potential failure modes within a system for classification by severity or determination of the effect of failures on the system. It is widely used in manufacturing industries in various phases of the product life cycle and is now increasingly finding use in the service industry Also known as FMEA.
- Pareto analysis Pareto analysis is a statistical technique in decision making that is used for selection of a limited number of tasks that produce significant overall effect. It uses the Pareto principle - the idea that by doing 20% of work you can generate 80% of the advantage of doing the entire job. Or in terms of quality improvement, a large majority of
- Fault tree analysis Fault tree analysis is a failure analysis in which an undesired state of a system is analyzed using boolean logic to combine a series of lower-level events. This analysis method is mainly used in the field of safety engineering to quantitatively determine the probability of a safety hazard
- Bayesian inference Bayesian inference is statistical inference in which evidence or observations are used to update or to newly infer the probability that a hypothesis may be true. The name "Bayesian" comes from the frequent use of Bayes' theorem in the inference process. Bayes' theorem was derived from the work of the Reverend Thomas Bayes
- Ishikawa diagram Ishikawa diagrams are diagrams that show the causes of a certain event. A common use of the Ishikawa diagram is in product design, to identify potential factors causing an overall effect, also known as the fishbone diagram or cause and effect diagram
- Cause Mapping - root cause analysis problem solving method that draws out, visually, the multiple chains of interconnecting causes that lead to an incident. The method, which breaks problems down specific cause-and-effect relationships, can be applied to a variety of problems and situations
- Barrier analysis - a technique often used in particularly in process industries. It is based on tracing energy flows, with a focus on barriers to those flows, to identify how and why the barriers did not prevent the energy flows from causing harm.
- Change analysis - an investigation technique often used for problems or accidents. It is based on comparing a situation that does not exhibit the problem to one that does, in order to identify the changes or differences that might explain why the problem occurred.
- Causal factor tree analysis - a technique based on displaying causal factors in a tree-structure such that cause-effect dependencies are clearly identified.
- Event and Causal Factor Charting - Another technique, where each event is enclosed in a rectangle. A series of events are enclosed in rectangles with lines inter connecting the rectangles. Events progress from left to right, just like in a text. Striking of a match stick is an event. If there is possibility of the interconnection, the rectangles are connected with the dotted lines. The 'Causes' are identified for each event. In order to diffrentiate the Causes from Events, Causes are enclosed in ellipse. The 'Presence of inflammable Gases' can be a 'Cause'. Both 'Event' and 'Cause' put together may lead to the accident, e.g., 'explosion'.
- TapRooT - A structured root cause analysis system built around a problem solving process with six embedded techniques to guide investigators beyond their current knowledge to the root causes of human performance and equipment failure related incidents.
- ARCA; Apollo Root Cause Analysis Apollo root cause analysis is a brand of root cause analysis method used to solve problems. As discussed in the article on Root cause analysis, there are many root cause analysis methods - A unique problem solving process characterized by a structured cause and effect chart known as a Realitychart which allows all problem stakeholders to own the problem and its corrective actions.
- RPR Problem Diagnosis RPR deals with failures, incorrect output and performance issues, and its particular strengths are in the diagnosis of ongoing & recurring grey problems . The method comprises: - An ITIL-aligned method for diagnosing IT problems.
Common cause analysis (CCA) common modes analysis (CMA) are evolving engineering techniques for complex technical systems to determine if common root causes in hardware, software or highly integrated systems interaction may contribute to human error or improper operation of a system. Systems are analyzed for root causes and causal factors to determine probability of failure modes, fault modes, or common mode software faults due to escaped requirements. Also ensuring complete testing and verification are methods used for ensuring complex systems are designed with no common causes that cause severe hazards. Common cause analysis are sometimes required as part of the safety engineering tasks for theme parks, commercial/military aircraft, spacecraft, complex control systems, large electrical utility grids, nuclear power plants, automated industrial controls, medical devices or other safety safety-critical systems with complex functionality.
Basic elements of root cause
- Materials
- Defective raw material
- Wrong type for job
- Lack of raw material
- Machine / Equipment
- Incorrect tool selection
- Poor maintenance or design
- Poor equipment or tool placement
- Defective equipment or tool
- Environment
- Orderly workplace
- Job design or layout of work
- Surfaces poorly maintained
- Physical demands of the task
- Forces of nature
- Management
- No or poor management involvement
- Inattention to task
- Task hazards not guarded properly
- Other (horseplay, inattention....)
- Stress demands
- Lack of Process
- Methods
- No or poor procedures
- Practices are not the same as written procedures
- Poor communication
- Management system
- Training or education lacking
- Poor employee involvement
- Poor recognition of hazard
- Previously identified hazards were not eliminated
- 4ME (Man, Machine, Materials, Method and Environment).
Also see
- Failure mode and effects analysis A failure modes and effects analysis is a procedure for analysis of potential failure modes within a system for classification by severity or determination of the effect of failures on the system. It is widely used in manufacturing industries in various phases of the product life cycle and is now increasingly finding use in the service industry
- Fault tree analysis Fault tree analysis is a failure analysis in which an undesired state of a system is analyzed using boolean logic to combine a series of lower-level events. This analysis method is mainly used in the field of safety engineering to quantitatively determine the probability of a safety hazard
- Forensic engineering Forensic engineering is the investigation of materials, products, structures or components that fail or do not operate/function as intended, causing personal injury or damage to property. The consequences of failure are dealt with by the law of product liability. The field also deals with retracing processes and procedures leading to accidents in
- Fix it twice
Categories: Quality
