Organizing the investigation
Defining the failure and its impact on the overall goals (Step #1) is based on answering a very specific set of four questions, something that typically takes less than five minutes. In the analysis step, when the causes-and-effect relationships are being identified, information is being discussed using timelines, diagrams and processes. People may offer some causes, explain the sequence of events, then review a process step, draw a picture and then go back to discussing causes. Regardless of what people offer it should be captured with the appropriate tool.
Some information will appear 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 those three basic questions common to every investigation--“What’s the problem?”. . . “Why did it happen?. . . “What can be done to prevent it from recurring?--and to appropriately organize all information. The following notes highlight the tools needed for organization of the collected information:
Capture the timeline. . .
A timeline, also known as a sequence of events, defines the chronological order of occurrences for a given issue. The simplest way to create a timeline is in a table format with date, time and description headers. Each entry, which should be a short phrase, not a complete sentence, corresponds to a specific date and time. 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. A cause-and-effect analysis is dependent on causes (the “why” questions). The timeline entry may be “9:05AM, Valve opened,” but the root causes of why the valve opened are located in the cause-and-effect analysis. A timeline should always be constructed for larger issues. Background information also can be added to the timeline instead of written being written on a separate paragraph. The time scale on a timeline can be based on years, days, hours, minutes or seconds—but it also can change throughout the timeline, as long as entry is placed in the proper chronological order. Timelines are very helpful tools in investigations. They complement thorough cause-and-effect analyses, but they don’t replace them. Many organizations mistakenly consider a timeline the analysis of the failure. Make sure that your organization doesn’t. Remember: Simply identifying the sequence of events does not explain the cause-and-effect relationships. |