Corollary: C1 regarding reality
What: Reality is actual but only accessible through human cognition
Why: We need to make explicit the notion that models are a representation of reality not the reality itself.
Corollary: C2 regarding worldviews
What: Systems models are created through the ‘spectacles’ of a set of worldviews.
Why: If models are a representation of our reality and not the reality itself we can think of the models as filters or spectacles through which we must look to see our reality.
Corollary: C3 regarding understanding
What: We can only control effectively what we understand.
Why: Perhaps this is self-evident but each of us understands in a different way. That is why we need to collaborate in teams to share understanding in different ways.
Corollary: C4 regarding embedment
What: Physical natural or artificial systems are ‘hard’ systems. Both are embedded in ‘soft’ people and social systems. Hard systems are objective whereas soft systems are subjective and intersubjective.
Why: This aspect of rigour sounds unduly ‘academic’ esoteric and remote from practice. However it underpins our understanding of uncertainty and the way we learn our way through it and so is important.
Corollary: C5 regarding functions
What: The purpose of a hard system is a function. The function of an artificial system is decided by us – it is man-made. A model of a natural system helps us understand the behaviour of a part of a reality. As a consequence we may ascribe a function to it.
Why: The function of man-made artefacts is a familiar concept to most of us. However the function of a natural system can be a source of confusion if we do not explicitly recognise that that function is ascribed by us through our models.