Process Failure Mode and Effects Analysis (FMEA) has become an important tool for identifying potential weaknesses in manufacturing processes. The Automotive Industry Action Group (AIAG) has published guidelines that help ensure that Process FMEAs are developed and interpreted in a consistent fashion. These guidelines, while very helpful, are still open to broad interpretation, and need further development and improvement, especially in the area of detection rankings. The current detection ranking criteria are very subjective, difficult to apply in a consistent fashion, and can easily be used to skew Risk Priority Number results.This paper will describe revisions to the guidelines for detection rankings that have been successfully used in developing Process FMEAs for automotive manufacturing processes. The revised guidelines are based on a number of factors including whether the cause or the failure is detected, the distance from the source, and the type of inspection used (manual or automated).The improved guidelines yield many benefits: 1) they make the tool easier to understand and use, especially for first-time practicioners; 2) they provide a direct relationship between the FMEA tool and the manufacturing environment; and 3) they ensure greater consistency in the creation and interpretation of Process FMEAs. Ultimately, the improved guidelines help ensure higher quality processes and products for all customers.