What is PD IEC/TR 63091 - Study for the derating curve of surface mount fixed resistors about?  
PD IEC/TR 63091 is a technical report that discusses a study for the derating curve of surface mount fixed resistors.
PD IEC/TR 63091 is applicable to SMD resistors with sizes equal to or smaller than the RR6332M, including the typical rectangular and cylindrical SMD resistors mentioned in IEC 60115-8.
Who is PD IEC/TR 63091 - Study for the derating curve of surface mount fixed resistors for? 
PD IEC/TR 63091 on study for the derating curve of surface mount fixed resistors is useful for: 
- Electric/electronic device designers and manufacturers
- Surface mount fixed resistor manufacturer
- Automotive electronic devices
Why should you use PD IEC/TR 63091-Study for the derating curve of surface mount fixed resistors?  
A derating curve is a graph that depicts how a component's maximum current rating falls as the ambient temperature rises.
PD IEC/TR 63091 helps you fulfil the demands from the electric and electronic device manufacturers for raising the power ratings safely. Additionally, it is required to establish a new derating curve that is suitable for the surface mount fixed resistors so that they can be used safely in a high-temperature environment, typically in automotive electronic devices.
Making a change of the temperature criteria for evaluating fixed resistors from ambient to connection point temperature will alter several stated contents. Furthermore, it will assist in modifying the users' assessment norms, resulting in a massive influence.
Thus, PD IEC/TR 63091 can assist you in accepting responsibility and carrying out the adjustments. This can ultimately lower the degradation rate while increasing the component's life expectancy and dependability. 
