Organizing the Investigation - 3 Steps & Tools
In the process of defining the problem and determining why it happened (root cause analysis) there are some other tools that prove very helpful and should be part of the incident documentation. Defining the failure and its impact on the overall goals in Step 1 is a very specific set of questions that typically takes less than 5 minutes. During or immediately after defining the problem people may begin offering additional information about the failure – in no particular order. People may offer causes, sequence of events, a process step that was skipped or they may draw a picture describing the layout or part.
Regardless of what people offer it should be captured in the appropriate tool. Some information will be in both the timeline and the cause-and-effect analysis. A diagram may contain a drawing of the part. The timeline may contain some history about the part and when it failed. The cause-and-effect analysis will contain the causes of why the part failed. The facilitator’s role is to keep the group focused on the three basic questions and organize all the information into its appropriate location(s). Following are some notes about the three investigation tools.
Capture the Timeline
A timeline defines the chronological order of occurrences for a given issue. A timeline is also referred to as a sequence of events. The simplest way to create a timeline is in a table format with the headers Date, Time and Description. Each entry on a timeline corresponds to a specific date and time. The entries on a timeline are much easier to collect and read if they are captured as short phrases instead of complete sentences. Long entries are easier to read if they are broken out sequentially and entered below the previous entry.
The timeline shows what happened at a specific date and time, but it does not explain why it happened. A timeline is dependent on time while a cause-and-effect analysis is depended on causes (why questions). The timeline entry may be “9:05AM, Valve opened”, but the causes of why the valve was opened are located in the cause-and-effect analysis. The timeline is always a vertical table of information while the cause-and-effect analysis (ThinkReliability Cause Map) branches out in different directions.
Larger issues always have a timeline. The background information can also be added to the timeline instead of written as a separate paragraph. Many companies include a background write-up, but the timeline is a simpler format that makes updates and edits much easier to do. The time scale on a timeline can be years, days, hours, minutes or seconds. The time scale can also change throughout the timeline as long as each entry is placed in the proper chronological order.
A timeline can be a very effective tool in investigation, but it’s not needed every time. The timeline complements a thorough cause-and-effect analysis, it doesn’t replace it. Many organizations consider a timeline the analysis of the failure – the timeline is their “investigation tool.” Simply identifying the sequence of events doesn’t explain the cause-and-effect relationships which are fundamental to a complete failure analysis. When investigating a problem, a timeline will always have a corresponding cause-and-effect analysis.
Use Diagrams, Drawings & Photos
Visual tools such as diagrams, drawings, sketches and photographs give everyone a common view of the issue. Without these, everyone has their own mental picture of the failure. A simple sketch on paper or a dry erase board immediately provides the group with a picture that everyone can edit, improve, point at and comment on. Don’t overlook the importance of a simple sketch. People are sometimes concerned about their artwork, but even a simple sketch can significantly improve the information exchange. The more detail that’s added to a drawing, the more specific the discussion can be. Mechanical drawings and diagrams from manuals or the original equipment manufacturers are also important during the investigation to improve on the accuracy of a sketch.
Photographs can also be very helpful because they can accurately capture consequences of the failure. Photographs provide a huge amount of context and detail in an investigation. A picture can significantly improve the amount of information conveyed about a failure. Digital cameras allow people to take plenty of pictures so that the most relevant can be selected. Digital photos can also be added directly to the electronic record as the investigation progresses.
Review the Processes
Identifying the processes that were in place before the failure occurred is extremely important in order to prevent the incident from occurring again. A recurring problem is symptomatic of not implementing solutions within the processes that created the failure. A thorough investigation must include a review of the processes that produced the failure. Similarly, a mechanic must know how the processes within a transmission work in order to explain how the transmission failed. During the investigation, a clear understanding of the current work process helps explain what specifically led up to the failure.
The process needs to be understood so that specific improvements can be made within the process to ensure that the failure doesn’t happen again. All of the action items (solutions) from the investigation are implemented in work processes upstream of where the problem(s) occurred.