A DFMEA (Design-FMEA) involves a study of a specific product. A PFMEA (Process-FMEA) is the study of a process that may produce products or provide a service. While the principles and strategy of a DFMEA and a PFMEA are essentially the same, the tactics used in some of the steps will differ somewhat.
A primary objective of a DFMEA is to uncover potential failures associated with the product such as those that could cause product malfunctions, a shortened product life or a safety hazard while using the product.
PFMEAs are used to uncover process problems related to the manufacture of a product or a series of products. When conducting a PFMEA, you need to think about how failures from the many process inputs or causes can affect process outputs such as product quality, processing efficiency and safety.