Systems theory and thinking has had an intimate relationship with formal instructional design practice since World War II.  At that time there was a growing focus on efficiency in training, since time – though scarce – was in ever increasing demand due to the increase in highly complex “man-machine” systems (Gibbons, 2013).  Since the training needs outweighed the amount of time available, a systems approach – with its emphases on life-cycle planning and developing “practical, usable solutions that implement existing theory as well as developing new theory along the way” (Gibbons, 2013) – became the most rational means to designing efficient training, particular within the military.

In 1965, Robert Gagné and colleagues published the influential work, Psychological Principles in System Development, which led to the systems approach becoming popular among instructional designers.  Once embraced among practitioners, the systems approach underwent a gradual simplification process resulting in the development of more than 40 such instructional design models by the end of the 70s (Andrews and Goodson, 1980, as cited in Reiser, 2001, p. 61).

Although there have been numerous attempts to identify the key steps within the systems approach as applied across various contexts, consensus indicates that the common feature within any systems approach is the application of the traditional scientific method to solve instructional problems (Richey et al, 2011).  Richey and colleagues (2011) further elaborate four additional qualities as unique contributions of general systems theory to the field of instructional design: “a consistent definition of system; the notion of purpose within a system; an emphasis on structure; and the concept of self-regulation”.  Interestingly, the notion of a system having a purpose is a key motivator in the creation of a new system to solve an existing problem that the original “purposeless” system failed to solve.  Likewise, the idea of a system being self-regulating forms the basis for the evaluation components to be designed within the system.

The systems approach was created to design solutions to complex problems (Richey et al, 2011; Gibbons, 2013) with many “unknowns and uncertainties” (Gibbons, 2013) and not for the analysis of single variables or events in isolation (Richey et al, 2011).  Unlike many of the current ID models – which stem from systems theory – that prescribe more rigid, procedural process approaches, a systems approach allows the instructional designer greater flexibility problem solving.  In reality, real ID problems are often complex with non-linear solutions, which must be analyzed and solved holistically with a greater consideration of the surrounding environments and interrelationships among various components.

Although systems theory reflect an “expansionist, nonlinear dynamic, and synthetic mode of thinking” (Banathy & Jenlink, 1996, p.74) that places synthesis over more analytical approaches to problem solving, it nonetheless has provided the theoretical foundation for more modern analytical, procedural ID models.  Richey et al (2011) summarize the application of general systems theory principles to modern ID theories and models as a two-step development that has consisted of 1) a conceptualization of the systems approach, and 2) the systems approach being proceduralized into the various instructional systems design models we have today.