Systems simultaneously have the characteristics of form and function. Form is what the ­system is. Function is what the system does. To aid in developing an understanding of form and ­function in systems and system thinking, we will use four running examples: an amplifier, a design team, the circulatory system, and the solar system. Figures 2.4 through 2.7 show simple illustrations or schematics of these four systems. Note that the examples are chosen to include built and evolved systems, as well as informational, organizational, mechanical, and natural systems.

Each of these systems clearly has a form. Form is what a system is; it is the physical or informational embodiment that exists or has the potential to exist. Form has shape, configuration, arrangement, or layout. Over some period of time, form is static and perseverant (even though form can be altered, created, or destroyed). Form is the thing that is built; the creator of the system builds, writes, paints, composes, or manufactures it. Form is not function, but form is necessary to deliver function.

Function is what a system does; it is the activities, operations, and transformations that cause, create, or contribute to performance. Function is the action for which a thing exists or is employed. Function is not form, but function requires an instrument of form. Emergence occurs in the ­functional domain. Function, performance, the “ilities,” and emergencies are all issues of functionality. Function is more abstract than form, and because it is about transitions, it is more ­difficult to diagram than form.

Function consists of a process and an operand. The process is the part of function that is pure action or transformation, and thus it is the part that changes the state of the operand. The operand is the thing whose state is changed by that process. Function is inherently transient; it involves change in the state of the operand (creation, destruction, or alteration of some aspect of status of the operand). In organizations, function is sometimes referred to as role or responsibilities.

We are now prepared to state Task 1 of System Thinking (Box 2.3).

Now we can apply this first task to our four running examples and identify their form and ­function, as summarized in Table 2.2.

For each of the built systems, there is an instrument of form, a process, and a value-related operand, whose change in state is the reason for the existence of the system. For the amplifier circuit, the output signal is the value-related operand. There may be more than one operand of a process (for example, the input voltage), but creating the amplified output signal is why we build this sort of device, and producing this amplified output signal is the primary function of the amplifier.

The design team (Team X) is a type of built system, in that someone assembled the team. The form is the collective of the individuals, and its primary function is to develop a design. In addition to its primary function, a built system may also deliver secondary functions. For example, Team X may also present the design. Primary and secondary functions are discussed in more detail in Chapter 5.

For natural systems, such as the solar system and the circulatory system, it is a bit more ­difficult to identify function. For the circulatory system, the form is clearly the collective of the heart, lungs, veins, arteries, and capillaries. The function could be expressed as supply oxygen to cells, as in Table 2.2 (supply is the process, and oxygen is the operand). But one could also say that the function is to absorb CO₂ from cells, or, more generally, to keep in balance the gas chemistry of the cells. In systems that have evolved (rather than ­having been designed), identifying a crisply defined function is a bit more difficult, because there is no statement of design intent from a designer. (In principle, we could talk with the designer of the amplifier circuit and Team X and ask, “What was the function you were trying to produce in the system?” or “What functional and performance emergence did you anticipate?”).

The solar system is even more of a challenge. The elements are unquestionable: the Sun, planets, and so on. But what is the function? An Earth-centric view might be that the solar system maintains Earth’s temperature to make life as we know it possible. This is certainly a function, but there are dozens of other formulations of the function of the solar system that are equally valid. The function listed in Table 2.2 is a more general statement: The solar system maintains an approximately constant solar energy flux to the planets. This is truly emergence, because it requires both a constant solar output and a roughly constant planetary orbital radius. The problem is not that the solar system does not have a function, but that it has so many! And it is very difficult to question the designer about design intent.

The distinction between form and function also appears in what business calls goods and services. Goods are products that are tangible (what we would call form). Services are products that are less tangible and more process-oriented (what we would call function). In fact, every system can be sold as form, which delivers value by performing the function. Or the system can be sold as function (service) that implicitly requires the instrument of form in order to be executed.

When Noam Chomsky developed transformational grammar, proposing the deep structure that underlies all human natural language, he found that the underlying structure of language has three parts: a noun that is the instrument of the action (what we call form), a verb that describes the action (what we call process), and a noun that is the object of the action (what we call the operand). The basic unit of all human language is the sentence, which has two nouns (the instrument and the operand) and one verb. Thus, this noun–verb–noun or instrument–process–operand model is either fundamental to all systems or fundamental to the way the human brain understands all systems. In either case, it is very useful!

In summary:

• All systems have form (what the system is) and function (what the system does). The form is the instrument of the function.

• Function further breaks down into process (the transformation) and the operand (the object that is transformed or whose state is changed).

• The primary function of most human-built systems is usually clear.

• The primary function of evolved systems is more difficult to discern and is often ­subject to interpretation.

• The proposed representation of a system (instrument form–process–operand) very closely resembles the deep structure of natural language (noun–verb–object).