The purpose of the FRAM is to analyse how something is done, has been done, or could be done in order to produce a representation of it. This representation is effectively a model of the activity because it captures the essential features of how something is done, using a well-defined format. In the case of the FRAM, the essential features are the functions that are necessary and sufficient to describe the activity and the way in which they are coupled or mutually dependent.
The FRAM has its own webpage here.
(c) Erik Hollnagel, 2019