In recent reviews of the development of systems science, a staged development has been recognised (Midgley, 2000). There seems to be a kind of agreement that a first wave covered by a fifty-year period ending around 1980 can be viewed as an expression of a functionalist approach, while a second wave, among others introduced by researchers such as Ackoff and Checkland, unfolded in the 1980s taking a mainly interpretive research orientation. The period from the 1990s until the present day is characterised by more uncertainty as concerns the wave categorisation. At least, however, what has been termed emancipatory and postmodern approaches candidate as important research orientations to feature a current third wave. Furthermore, recent ideas stemming from complexity research are found to be relevant in this context. Today the approaches are used concurrently when seeking to make sense of complex problems; thus the waves and their approaches have not superseded each other but have successively contributed to expanding and enriching systems thinking, see also (Stowell & Welsh, 2012).
The third wave of systems science is based on the previous functionalist and interpretive orientations, which – quoted from Systems Approaches to Management by Jackson – can be characterised as follows: