Abstract
A balancing loop compares where things are with where they're supposed to be, then acts to close the gap. A thermostat works this way. So does a manager who hires when the team falls behind. The bigger the gap, the harder the correction.
Loops like this keep things stable, which is also why change often gets undone: move a system away from its goal and the correction brings it back. When the information or the action arrives late, the correction overshoots and the system swings back and forth around the target.
Method
- 01
Name the goal
Write down the state the loop is trying to reach or hold. Sometimes it's written down somewhere and sometimes it's an unspoken norm.
- 02
Measure the gap
Compare where things are with the goal. The size of the gap drives the correction.
- 03
Describe the correction
When there's a gap, who notices and what do they do about it?
- 04
Find the delays
List the lags between acting and seeing the result. Long delays are the usual reason for overshoot.
- 05
Check whether the goal is drifting
When a gap won't close, people often lower the goal instead. Watch for standards that slip a little every year.
When to use it
- A change you made keeps getting undone.
- Something swings back and forth around a target, such as stock levels or staffing.
- You want to understand why a standard has slowly slipped.
Common pitfalls
- Correcting harder when results are slow to show. Strong corrections plus long delays make the swings bigger.
- Missing the unwritten goal. A lot of resistance comes from a balancing loop whose target nobody wrote down.
- Fighting the loop head on. It's usually easier to change its goal or the information it acts on.
- Letting the goal drift because closing the gap is hard.
Origin and references
Attributed to Jay W. Forrester, system dynamics (1961).
- Forrester, J. W. (1961). Industrial Dynamics. MIT Press.
- Meadows, D. H. (2008). Thinking in Systems: A Primer. Chelsea Green Publishing.
- Sterman, J. D. (2000). Business Dynamics: Systems Thinking and Modeling for a Complex World. Irwin McGraw-Hill.