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Ternary Analysis


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Stages in the design and construction of work and tasks

Guidelines can be derived from Ternary Analysis for the design of work processes and of tasks.

Work is a purposive activity, and from this it follows that a third paradigm for purpose and directiveness should be adopted, rather than either the first, or Aristotelian, one or the second, or early cybernetic, one (Stewart, 1999a).

The first paradigm

The Aristotelian paradigm was the early teleological conception, based on Aristotle's doctrine of the four causes, that has sometimes been seen as inconsistent with mechanistic conceptions, such as those of the Darwinian and Cybernetics schools.

The second paradigm

The founders of cybernetics decided that information is as much a physical quantity as are matter and energy. This implied the need to augment classical natural science by adding to it a second domain (defined as open to energy but closed to information and control) to accommodate the resulting new concepts. The result was to create the concept of binary (i.e. two-domain) mechanism. However, this approach still left unresolved many of the original problems raised by mechanistic conceptions of purposiveness.

The third paradigm

I have proposed that, to avoid such difficulties, physical science again needs to be augmented: by the addition of a third domain (split from the second by a discontinuity derived from Hume's Law), this time to accommodate concepts relating to preference and justification (Stewart, 1989). The result is to create the concept of ternary (i.e. three-domain) mechanism. I have suggested that, in this way, it is possible to go beyond mechanism as it was originally understood, and to dissolve the remaining objections to it.

Figure button   Paradigms for purpose and directiveness

The practical outcome of adopting this third paradigm is the realisation that it is no use merely to adopt a teleological expression of the objective and to expect that this will somehow give rise to an effective purposive mechanism.

Construction of a task

Do not expect the teleological statement alone to bring about the desired result. It is essential to design the task, or the work, in all three domains (Stewart, 1999b), in the form of a ternary mechanism.

The causal mechanism, constructed of causal nexi, has to be considered. To illustrate how this is done in Ternary Analysis, let us examine the tern of Nexus.

You may remember Ashby's exposition of kinematic graphs, and that these are tables or networks of links between events (Ashby,1956). The link is of the form A is always transformed to B.

Because Ashby insists that the only domain of interest to cybernetics is the secondary one so, for him, this is a unary mechanism. He is not concerned with any material causation which may be going on in the system which he is describing.

But, if we look in the primary domain, we will probably see that there is a causal nexus of some kind between the events A and B. Regarded as a binary mechanism, it is one in which the causal nexus in the primary domain expresses the transformation in the secondary domain.

At this stage, the kinematic graph is not describing a purposive mechanism. But we can go a stage further, and add a tertiary domain. We could then handle the possibility that event A is part of a situation which is in some way less desirable than the situation that would obtain if event B occurred. If the primary nexus is actuated, to express the secondary nexus and result in event B happening, then we can say that the tertiary nexus being expressed is of the form in order that.

What we now have is a tern of nexus, which consists of {cause - transformation - in order that}, and the tertiary component of nexus is where purpose, teleology, and imparity fit into the mechanism.

Figure button   The tern of Nexus

To summarise, then:

The process of design of such a mechanism is in three stages:

1. Start with a statement of ultimate purpose. Analyse this into a structure of purposes and sub-purposes. If a version of the task, or the work, already exists, then analyse it and map its tertiary structure.

2. Impress this tertiary structure on a kinematic graph ensuring that it will act so as to express the purposes.

This yields the secondary structure.

3. Devise a primary structure, the causal activity of which will express the secondary structure required.

In brief, start with your purposes fully understood, then construct a ternary mechanism to express them.

Figure button   Ternary construction of a task



© Copyright D J Stewart 1999, 2003. All rights reserved.