What is Change Analysis?
Change Analysis is a root cause analysis technique that focuses on a specific problem or problematic event. This type of analysis seeks to expose which deviation from regular procedure, or change, drove the unfavorable event. This is the type of analysis manufacturing folks typically think of when discussing change analysis.
Change analysis is easy to learn and apply. Looking for a deviation from a norm also results in a clear corrective action. This provides concrete next steps for anyone conducting the analysis. Furthermore, it makes it easier to detect unusual root causes.
Consider applying a different type of root cause analysis if your standard process isn’t well defined enough to provide a good basis for comparison. Also, depending on how variable your processes are, the number of moving parts might significantly increase the scope of this type of analysis.
Whether you decide to apply this type of analysis or another form of root cause analysis, make sure to test your assumptions. In the worst case scenario, you’ll determine that your hypothesis is inconclusive or fail to find an actual root cause. This result, while unpleasant, is better than drawing an incorrect conclusion that causes additional issues in the future.
What is Barrier Analysis?
Barrier analysis is a systematic process used to identify failures of physical, administrative, and procedural barriers that should have prevented the adverse event. This analysis identifies why the barriers failed and determines which types of corrective action are needed to prevent it from failing again in the future.
Start your barrier analysis by identifying all of the barriers that were in place before the adverse event occurred. Review each barrier to determine if it was functioning under normal operating conditions. If there was a deviation in operating conditions, was it performing its intended function under these conditions? Did the barrier help decrease the total cost of the adverse event? Was the barrier’s design strong enough to fulfill its intended purpose? Finally, review whether it was built, maintained, and inspected appropriately leading up to the event.
Use these questions with each barrier to identify how the barriers failed to prevent the event. Note that this may not be the best type of root cause analysis depending on what you are investigating and the state of the existing process or set up leading up to your event.
What is Risk Tree Analysis?
Risk tree analysis, like the previous two analyses we’ve reviewed, is used to analyze the effects of a failed system after an adverse event has occurred. Event trees were developed during the WASH-1400 nuclear power plant safety study in 1974. Fault tree analysis under certain circumstances become large and unruly. The event tree was developed to help identify which pathway creates the most significant risk for a failure in a system without requiring each path to be mapped out in the tree.
The risk tree analysis has a few benefits. First, it helps you identify multiple coexisting contributors to failure. This provides multiple layers of detail. On the flip side, the amount of detail available in this analysis can make it easy to overlook subtle differences between branches. Also, this is a more complex form of root cause analysis. The person conducting the analysis needs training and some experience to ensure success.
What is the Kepner-Tregoe method?
The Kepner-Tregoe method of root cause analysis became famous when NASA used it to bring the Apollo 13 team home. It’s a structured methodology for gathering, prioritizing, and evaluating information. Like other forms of root cause analysis, the Kepner-Tregoe method is a systematic approach to solving a problem and analyzing risk.
The first step in this methodology is to identify problems and classify them by level of concern. Then, set the priority level by potential impact, urgency, and growth. Next, decide what action to take or which step to take next. Finally, make a plan for who will be involved, what they will do, where they’re involved, and when they take part. Be sure to scope the extent of each person’s involvement.
The next step to applying this analysis is to determine which objectives must be accomplished, as well as which ones you want to accomplish that aren’t absolutely necessary. This will help you evaluate your options against your objectives so you can determine the best possible choice of action.
The key benefit of the Kepner-Tregoe analysis is the ability to prioritize and focus the analysis. By weighing and setting objectives, this type of analysis provides a more direct review of an issue.