Root Cause Analysis & ISO 9001:2015
Root Cause Analysis
Amelia Fisher, Audit Manager
If nonconformities are identified within your Quality Management System (QMS), the ISO 9001:2015 standard requires you to analyze the root cause and describe the specific correction and corrective actions taken, or planned to be taken, in order to eliminate the detected nonconformities. The following tools are a perfect start to determining the root cause of a nonconformity.
The 5 Whys
“The 5 Whys” technique uses a question-asking method to explore the cause-and-effect relationships underlying the problem. Essentially, the problem-solver asks “why” until a relevant conclusion is reached. Generally, a minimum of five questions should be asked, although additional questions are sometimes required if the real cause is yet to be identified after five questions, rather than simply settling for a partial conclusion. Partial conclusions are seen as symptoms to the root cause and if only a symptom is corrected or treated, the problem is likely to occur.
The basic premise behind brainstorming as a root cause analysis tool is that a group of people working collectively to find a solution is more productive and innovative than if each person tried to come up with a solution individually. The brainstorming process brings a group of people together to discuss the issue in question.
The brainstorming process starts by scheduling a meeting and informing the participants of the topic to be discussed. One individual is assigned to write down thoughts that are presented and all participants are given equal opportunity to participate. The resulting discussion ideally identifies the root cause of the problem and presents an opportunity to resolve it.
Fishbone diagrams are also known as cause-and-effect diagrams and are most useful when the “5 whys” is too basic. In a fishbone diagram, the problem or nonconformity, is put at the head of the diagram and various causes are grouped into categories such as equipment, processes, measurements, materials, environment, and people. Arrows in the image split off like bones in a fish to indicate how the causes flow toward the nonconformity.
This type of root cause analysis attempts to understand the possible causes by asking questions such as “what happened,” “when,” “where,” “why,” “how,” and “so what” until a possible cause is identified.
Using more than one root cause analysis tool to solve a problem is effective and often necessary. For example, although brainstorming can bring to light several theories as to why a problem is occurring, the data can be difficult to confirm. Organizing factual data into a fishbone diagram and then seeking out objective evidence can substantiate the theory and ultimately lead to a more accurate solution.