When zooming into an activity system, it becomes a chain of sub-activity systems (i.e. an internal supply chain). When zooming out, the activity system is seen as a link in a chain of sub-activity systems of an overarching activity system (i.e. as part of an external supply chain).
For example, zooming into the eating activity system one can identify sub-activity systems like putting food into the mouth, chewing and swallowing. By zooming out, eating becomes a link in the nutrition chain of growing, producing, preparing, eating, digesting, metabolising and absorbing food.
An activity system is an organised process. A sub-activity system is an organised process phase.
Process is concerned with transforming input substance into an output substance. Transformation means that the output substance is qualitatively different than the input substance. For example, cake ingredients get processed (or transformed) into a cake. The processing can involve different phases. For example, the cake ingredients are assembled, mixed into dough and baked. These phases represent the sub-activity systems.
The output of each phase (sub-activity system) is qualitatively different than that of the previous one. This indicates that value has been added. Thus supply chains are also referred to as value chains.
To achieve the overarching aim of the supply chain, the aims of all sub-activity systems need to be aligned and their organisation compatible with each other. For example, to produce a fluffy cake, the dough has to be mixed to a fine consistency, not a crumbly one.
relevance
Each (sub)sub-activity system links up with others, one taking up its products and another taking up its by-products. The exquisite ecological balance observed in nature demonstrates the usefulness of all outputs. “Pollution is nothing but the resources we are not harvesting. We allow them to disperse because we’ve been ignorant of their value.” (Buckminster Fuller)
relevance for the change manager
Any activity (or process) system (re)design involves identifying, rearranging and changing chains of (sub)activity systems according to an overarching aim and design.
what is the relevance of this concept for you?