ISO 12110-2:2013 presents cycle counting techniques and data reduction methods which are used in variable amplitude fatigue testing. For each test or test series, cycle counting is mandatory whereas data reduction methods are optional.

ISO 12110-2:2013 supports ISO 12110-1 which contains the general principles and describes the common requirements about variable amplitude fatigue testing. ISO 12110-2:2013, the term "loading" refers either to force, stress, or strain since the methods presented here are valid for all.

The following issues are not within the scope of this document and therefore are not addressed: constant amplitude tests with isolated overloads or underloads; large components or structures; environmental effects like corrosion, creep, etc. linked to temperature/time interactions leading to frequency and waveform effects; multiaxial loading.