Root cause analysis

Root cause analysis is the process of looking for the reasons why a problem is occurring. By correcting the underlying root causes of problems, the incidence of the problems can be greatly reduced or eliminated.

Root cause analysis tends to uncover issues related to the failure of materials, an error by a person, or an organizational issue (such as an incorrect work instruction, procedure, or form).

It is quite possible that finding and correcting a single root cause will not completely eliminate a particular problem. If so, root cause analysis can be conducted on a recurring basis, to gradually locate and eliminate a series of issues. Eventually, the number of times the triggering problem arises may decline to the point where additional effort is considered unnecessary, though there may be additional root causes still causing problems; the remaining issues are simply considered too immaterial to pursue, or their correction is not cost-effective.

Root cause analysis can be used in a variety of areas. For example, it can be used to uncover the reasons for incorrect billings, product failures, and vehicle accidents on a particular stretch of road. It is most heavily applied to the resolution of product failure issues, but can be readily adapted to the analysis of failures in company processes.

Root cause analysis may require a considerable amount of detailed investigation, not only to find a root cause, but also to generate several possible solutions that will correct the root cause. The solution selected will usually be the simplest or least expensive alternative available, and one that does not trigger a new root cause that leads to a new problem or reinforces an old problem.

Once a sufficient history of root cause analysis projects have built up within a firm, it is possible to apply this history to projected new processes and products to predict failures that may occur. Doing so allows a business to make corrections before a process or product implementation begins.

For example, a company finds that there is a high return rate by customers for its baby stroller product, because there are repeated instances where the wheels fall off. After conducting a root cause analysis, the company finds that the nut used to tighten the wheels onto the axles has the wrong specifications, which it corrects on the next purchase of nuts from a supplier. As a result, the company finds that product returns are reduced, but do not go away, due to the same complaint. Additional root cause analysis finds that the axle onto which the nut is tightened can break off, due to metal fatigue. As a result, the company buys the axle component with more stringent specifications, after which the returns issue is eliminated.

Root cause analysis is a proactive approach to solving problems, and so can also trigger a turnaround from a company culture that was previously reactive, only responding to problems after they had already occurred.