Once the DFMEA is completed, the PFMEA can be developed to control the production process. At Watlow, PFMEA documents are developed based on part numbers. This means the PFMEA lists the steps for the build of a part from receipt of materials through to shipping. The disadvantage of this approach is that when a change is made to a process common to more than one part number, all PFMEA documents containing references to that process must be changed. Using a process structure — versus the part number structure — it becomes clear as to the benefits gained by focusing on the process. Take Watlow’s induction braze process as an example. If a PFMEA is developed for induction brazing, it can be applied to all part numbers that utilize the induction braze process. When improvements are made to the induction braze process, updates are made to the PFMEA specific to this process. The benefit is that only one change must be made on one document to cover all part numbers that use this process. Additionally, the PFMEA can be used to prioritize improvement using a RPN for a process that relates to many part numbers.
Subscribe today to receive the INSIDER, a FREE e-mail newsletter from Embedded Technology featuring exclusive previews of upcoming articles, late breaking NASA and industry news, hot products and design ideas, links to online resources, and much more.