How are tolerances applied to the requirements?
For any performance metrics that are measured as a percentage, corresponding tolerances refer to percentage points. For example, a power factor requirement of ≥ 0.90 (i.e. ≥ 90%) with a -3% tolerance implies a functional requirement of ≥ 0.87 (i.e. ≥ 87%). For performance metrics that are not measured as a percentage, the tolerance is a percentage of the required value. For example, for a minimum efficacy requirement of 60 lm/W with a -3% tolerance, the functional requirement is 58.2 lm/W (i.e. 60 – 3% = 58.2).