When the relevant interactions are identified it's appropriate to identify which elements are the responsibility of which stakeholders, which elements are part of the addressable interactions and which elements are part of the environment. There is a also a video
for this insight which is a component of the Effective Problem Solving Course
Identifying responsibilities is important for several reasons.
A understanding the separation between what represents the situation and its environment that serves as a context for the situation.
Within the context of the situation there are multiple elements considered to be directly part of the addressable situation.
There are a number of elements which are part of the environment which may be influenced or provide influence though which are for one reason or another not able to be altered.
Within the context of the situation it is essential to identify which stakeholders are responsible for which elements for only they can effect a change to the nature of those elements and engage in altering influences.