While the Tavistock legacy is directly associated with "Human Relations" 
, the centrality of systems thinking in the three research perspectives that emerged could also be labelled as Social Systems Science .
A revisiting of the three perspectives in 2012 reaffirmed that they all developed at the same time.
[... the] socio-psychological, the socio-technical and the socio-ecological perspectives ... emerged from each other in relation to changes taking place in the wider social environment. One could not have been forecast from the others. Though interdependent, each has its own focus. Many of the more complex projects require all three perspectives. [Trist & Murray 1997, p. 30]
The socio-psychological systems perspective was the earliest to be published.
... in Institute projects, the psychological forces are are directed towards the social field, whereas in the the Clinic, it is the other way around [with social forces directed toward the psychological field].
[Trist & Murray 1997, p. 31]
The socio-technical systems perspective is the most well known.
... the best match between the social and technical systems of an organization, since called the principle of joint optimization.
... the second design principle, the redundancy of functions, as contrasted with the redundancy of parts.
[Trist & Murray 1997, p. 32]
The socio-ecological systems perspective came into prominence as the apparent pace of change in the world accelerated.
... the context of the increasing levels of interdependence, complexity and uncertainty that characterize societies a the present time.
... new problems related to emergent values such as cooperation and nurturance.
[Trist & Murray 1997, p. 33]
Much of the conventional wisdom on how organizational systems work today comes from this original research.
Trist, Eric L., Hugh Murray, and Frederick Edmund Emery. 1997.
The Social Engagement of Social Science: The Socio-Ecological Perspective. Vol. 3. University of Pennsylvania Press.
http://www.moderntimesworkplace.com/archives/ericsess/sessvol3/sessvol3.html .
While the Tavistock legacy is directly associated with "Human Relations"
, the centrality of systems thinking in the three research perspectives that emerged could also be labelled as Social Systems Science 
.
A revisiting of the three perspectives in 2012 
reaffirmed that they all developed at the same time.
The socio-psychological systems perspective was the earliest to be published. The socio-technical systems perspective is the most well known. The socio-ecological systems perspective came into prominence as the apparent pace of change in the world accelerated. Much of the conventional wisdom on how organizational systems work today comes from this original research. Trist, Eric L., Hugh Murray, and Frederick Edmund Emery. 1997. The Social Engagement of Social Science: The Socio-Ecological Perspective. Vol. 3. University of Pennsylvania Press. http://www.moderntimesworkplace.com/archives/ericsess/sessvol3/sessvol3.html