In the provided sources, setting a system boundary is not a physical given but a subjective, cognitive act performed by an observer based on their purpose or perspective[1]. You can cluster the criteria for setting these boundaries and the questions to ask into five primary domains:

1. Functional Control and Influence

The most common criterion for setting a boundary is the degree of control a decision-maker has over specific elements[6].

The System: Consists of those components that can be strongly influenced, controlled, or designed by the decision-makers[9].

The Environment: Consists of factors that influence the system but are not controlled by it[6].

Questions to Ask:

    ◦ Can the decision-maker change this factor, or must they adapt to it as a “given”?[6][14]    ◦ Does this element affect the system’s performance?[12][15]    ◦ Is this a resource (controllable) or a constraint (uncontrollable)?[13]

2. Strategic Framing and Purpose

Boundaries are often defined by the “intelligence” or goal of the inquirer. This cluster views the system as a “system of interest” rather than a physical object[2].

The System: A conceptual device chosen to make sense of a particular “mess” or problem[3].

The Environment: The “white space” or “context” that makes the system’s actions meaningful[15].

Questions to Ask:

    ◦ What is the purpose of this inquiry or model?[9]    ◦ What “variety” (complexity) must be included to achieve our goals, and what can be safely ignored as “noise”?[27][28]    ◦ Are we viewing this as a “narrow system of interest” or a “wider system” we merely wish to influence?[29][30]

3. Ethical and Critical Responsibility

This cluster treats boundary-making as a political and moral act that determines who is valued and who is marginalized[31].

The System: The beneficiaries and those involved in the decision-making process[32].

The Environment: Those who are affected by the system but have no control over it (the “victims”)[14].

Questions to Ask:

    ◦ Who is the beneficiary of this system, and who is the “victim” or “enemy”?[14][32]    ◦ What resources and conditions ought to be part of the system rather than the environment?[32][33]    ◦ Whose interests are being served by drawing the boundary in this specific place?[32][34]

4. Rate of Change and Frequency

In hierarchical and biological systems, boundaries are set based on the relative speed of interactions[35][36].

The System: Operates at a high frequency (fast behavior)[37].

The Environment: Changes much more slowly, appearing constant to the system’s internal cycles[37].

Questions to Ask:

    ◦ Where is the “frequency cut”? What is changing so slowly that it acts as a stable constraint?[37][38]    ◦ Where do interactions become “weak” or infrequent compared to the core behavior?[39][40]

5. Complexity and Informational Capacity

Cybernetic thinkers set boundaries based on the Law of Requisite Variety, distinguishing between internal order and external chaos[41][42].

The System: A “variety reducer” or filter that maintains a lower state of entropy than its surroundings[43].

The Environment: A generator of infinite variety that throws disturbances at the system[46].

Questions to Ask:

    ◦ Does the system have enough internal variety to match the variety of the environment?[41]    ◦ How does the system transduce (filter) environmental variety into meaningful signals?[22][50]    ◦ Is the system reaching its “energy budget” in trying to respond to environmental stimuli?[51]