When a control system is humming along, the gap between the desired and current states is so small that the frequency of command issuance by the Decision Maker component is essentially zero; all is well and goal attainment is on track. However, with the universe being as messy as it is, unseen and unpredictable “disturbances” can, and do, enter the system at any point of access to the structure.
If the sensors and/or actuators can’t filter out the disturbances or are malfunctioning themselves, then true control of the production system may be lost. Perceptions and commands get distorted and the distance between goal attainment and “reality” will be perceived as shorter or longer than they are. D’oh! I hate when that happens.
Given the generic control system model below, how can we improve the performance of an underachieving production system?
One performance improvement idea is to make the goal directly visible to the production system; as opposed to indirectly via the policy/process actions of the actuators.
A meta-improvement on this idea is to allow the production system constituents direct involvement in the goal setting process.
It seems to make naive sense, doesn’t it? Well, it does unless the goal is some arbitrarily set financial target (“increase market share by 10%“, “decrease costs by 5%“, “increase profits by 25%“) pulled out of a hat to temporarily anesthesize Wall Street big-wigs.
First, let’s look at a fully functional control system:
As long as the (commands -> actions -> CQs -> perceptions) loop of “consciousness” remains intact, the system’s decision maker(s) enjoy the luxury of being able to “control the means of production“. Whether this execution of control is effective or ineffective is in the eye of the beholder.
As the figure below illustrates, the capability of decision-makers to control and/or observe the functioning of the production system can be foiled by slicing through its loop of “consciousness” at numerous points in the system.
From the perspective of the production system, simply ignoring or misinterpreting the non-physical actions imposed on it by the actuators will severely degrade the decision maker’s ability to control the system. By withholding or distorting the state of the important “controlled quantities” crucial for effective decision making, the production system can thwart the ability of the decision maker(s) to observe and assess whether the goal is being sought after.
In systems where the functions of the components are performed by human beings, observability and controllability get compromised all the time. The level at which these “ilities” are purposefully degraded is closely related to how fair and just the decision makers are perceived to be in the minds of the system’s sensors, actuators, and (especially the) producers.
The figure below models a centralized control system in accordance with Bill Powers’ Perceptual Control Theory (PCT).
Given 1: a goal to achieve, and 2: the current perceived state of the production system, the decision-making apparatus issues commands it presumes will (in a timely fashion) narrow the gap between the desired goal and the current system state.
But wait! Where does the goal come from, or, in cybernetics lingo, “who’s controlling the controller?” After all, the entity’s perceptions, commands, actions, and controlled quantity signals all have identifiable sources in the model. Why doesn’t the goal have a source? Why is it left dangling in an otherwise complete model?
Abstraction is selective ignorance – Andrew Koenig
Well, as Bill Clinton would say, “it depends“. In the case of an isolated system (if there actually is such a thing), the goal source is the same as the goal target: the decision-maker itself. Ahhhh, such freedom.
On the other hand, if our little autonomous control system is embedded within a larger hierarchical control system, then the goal of the parent system decision maker takes precedence over the goal of the child decision maker. In the eyes of its parent, the child decision maker is the parent’s very own virtual production subsystem be-otch.
To the extent that the parent and child decision maker’s goals align, the “real” production system at the bottom of the hierarchy will attempt to achieve the goal set by the parent decision maker. If they are misaligned, then unless the parent interfaces some of its own actuator and sensor resources directly to the real production system, the production system will continue to do the child decision maker’s bidding. The other option the parent system has is to evict its child decision maker subsystem from the premises and take direct control of the production system. D’oh! I hate when that happens.