RDMs are usually related to cumulative degradation processes although within this document they are also used in the context of single event effects (SEE). In such context, the definition of RDM is adapted differently for the two separate cases of destructive or non-destructive single events (see definitions 3.2.48 and 3.2.49).
Since in the case of SEE the RDM definition can be linked to the SEE rate or risk, the RDM can change depending upon the phase of the mission (e.g. whether a payload system is intended to be operational at particular times) and local environment or space weather conditions (e.g. if the spacecraft is passing through the South Atlantic anomaly or during a solar particle event). Since SEE rate or risk prediction is based on use of test data and simplifying assumptions on the geometry and interactions, it is important to take into account the potential for large errors in predicting SEE rates when establishing the reliability requirements for equipment, and especially for critical equipment. Derating can also be used to reduce or remove susceptibility to SEE.