tailieunhanh - Root Cause Failure Analysis Part 2

Tham khảo tài liệu 'root cause failure analysis part 2', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 22 Root Cause Failure Analysis When did it happen What changed Who was involved Why did it happen What is the impact Will it happen again How can recurrence be prevented What Happened Clarifying what actually happened is an essential requứement of RCFA. As discussed earlier the natural tendency is to give perceptions rather than to carefully define the actual event. It is important to include as much detail as the facts and available data permit. Where Did It Happen A clear description of the exact location of the event helps isolate and resolve the problem. In addition to the location determine if the event also occurred in similar locations or systems. If similar machines or applications are eliminated the event sometimes can be isolated to one or a series of forcing function s totally unique to the location. For example if Pump A failed and Pumps B c and D in the same system did not this indicates that the reason for failure is probably unique to Pump A. If Pumps B c and D exhibit similar symptoms however it is highly probable that the cause is systemic and common to all the pumps. When Did It Happen Isolating the specific time that an event occuưed greatly improves the investigator s ability to determine its source. When the actual time frame of an event is known it is much easier to quantify the process operations and other variables that may have contributed to the event. However in some cases . product-quality deviations it is difficult to accurately fix the beginning and duration of the event. Most plant-monitoring and tracking records do not provide the level of detail requừed to properly fix the time of this type of incident. In these cases the investigator should evaluate the operating history of the affected process area to determine if a pattern can be found that properly fixes the event s time frame. This type of investigation in most cases will isolate the timing to events such as the following Production of a specific product. Work schedule of a