Control Theory

Effective control requires five things:

1. a goal
2. a sensor
3. a comparator (goal vs. reality)
4. a corrective action
5. a cadence.

Keeping your house at 72°F in winter.

1. Goal: 72°F indoor temperature.
2. Sensor: The thermostat’s thermometer, which reads the actual room temperature.
3. Comparator: The thermostat’s circuit compares the set point (72°F) against the current reading (say, 65°F). There’s a 7-degree gap.
4. Corrective action: The thermostat kicks on the furnace. It runs until the gap closes.
5. Cadence: The thermostat samples the temperature every few seconds, continuously.

This is basically why folks care about things like Service Levels and even rituals like Sprint planning.