APS does not identify biological explanation with the reduction of phenomena to smaller physical parts.
Reduction, decomposition, and material analysis can provide powerful explanatory resources, including the identification of components, mechanisms, interactions, and causal processes. Mechanistic explanation, however, should not itself be equated with reductionism: mechanisms may involve dynamically organised relations, regulation, feedback, environmental interaction, and processes extending across spatial and temporal extents.
APS makes living organisation an explicit explanatory target. It investigates how biological activities relate to viability-oriented, constraint-closed organisation and to the maintenance and re-establishment of conditions required for continued functioning through change.
This does not imply that every adequate biological explanation must include an APS organisational account, or that mechanistic explanations become intelligible only when placed within APS. For particular explananda, mechanistic, reductive, organisational, or other explanatory approaches may make different and potentially sufficient contributions.
Where APS and another approach address the same explanatory target, their relative explanatory contribution must be assessed rather than inferred from the distinction between organisation and reduction.