The first thing to consider when dealing with the connection between the Design Failure Mode Effective Analysis (DFMEA) and Special Characteristics is that the DFMEA documents functionality and NOT characteristics. The question then becomes how we convert these important functions into characteristics.  

Characteristics must be gathered from these important functions when combined with an associated requirement. Now you might be a little bit uncomfortable with that concept. An illustration of this can be seen in an example of a simple drinking cup. If you performed a DFMEA around a simple drinking cup something that may be a requirement would be to hold a certain volume of liquid. 

For example: the function of the cup is to hold liquid, while the requirement is to hold specifically 18 oz. When the function is combined with the requirement then it becomes a special characteristic.  

Function + Requirement = Special Characteristic 

There can be exceptions and there can be some characteristics that do arrive on the DFMEA but for now let us think about think of the DFMEA as dealing in important functions. For any designers out there, any characteristic you include on the print that you want to fulfill then becomes important*. 

For more information around special characteristics check out our other blog posts, or contact us to learn more about customized workshops for your team. 

*Refers to Special, Critical, or Important Characteristics 

**Note: These do not need to be called “special characteristics” other nomenclature can be: key characteristics, critical characteristics, or regulatory characteristics. In the video above Jeremy references them as “special” or “important.”