Balancing Loop

A balancing loop attempts to move some current state (the way things are) to a desired state (goal or objective) though some action (whatever is done to reach the goal).The balancing loop is one of the two foundational structures of systems thinking, the other being the Reinforcing Loop. A balancing loop is representative of any situation where there is a goal or an objective and action is taken to achieve that goal or objective. If I decide I want to increase sales by 10% I've just created a balancing loop. If I decide to develop a new product I've just created a balancing loop. The instances of this structure are numerous.

The desired state interacts with the current state to produce a gap. The desired state is considered to be fixed during this consideration. The gap created by the difference between the desired state and the current state is really the motivation for action, and the larger the gap the grater the tendency to produce action. The action taken then adds to the current state. The current state subtracts from the gap, thus reducing it. When the action succeeds in moving the current state to a point where it is equal to the desired state the gap is reduced to zero and there is no more motivation for action.

Effective Strategies

Ensure there is an explicit well understood and agreed upon definition of the desired state. If you don't know where you're trying to get to then any action will take you somewhere.
Ensure there is an as objective as possible definition of the current state. It is the relation between the desired state and the current state that forms the basis for planning and subsequent action. If the planning is flawed there is a good chance the resultant action will be inappropriate to move the current state to the desired state.
Because action is driven by the size of the gap there is a natural tendency for the extent of action to decline as the current state approaches the desired sate. This tendency accounts for the fact that as projects approach completion it seems to be more and more difficult to make progress toward completion. To overcome this tendency the motivation for action must come from somewhere else other than the gap. In terms of project completion the focus might be to begin to think about completing this project so the organization can get on to the next one. The answer to the predicament lies outside the structure.

Areas of Concern

The balancing loop is one of the simplest structures and seldom ever occurs in isolation from additional influences. The most prevalent extensions of the balancing loop are identified in the following areas of concern.

Since you can never do just one thing, and the fact that the current state is what it is for some reason, the action taken to change the current state, or the change in the current state itself, may produce side effects which in fact cause the current state, in time, to return. For insights into this situation see Fixes that Fail.
If the period of time over which it takes action to move the current state to the desired states is relatively long there may be a willingness to settle for less than the initial desired state. In this instance the goal is never reached because the goal is lowered over time. For insights into this situation see Drifting Goals.
Pursuing this desired state may cause problems elsewhere. These problems may actually result in increasing the goal making it more difficult to reach. For insights into this situation see Escalation.
The situation may be such that the action taken to achieve the goal actually causes the current state to overshoot the goal. This would then require additional action to bring the current state back toward the goal. For insights into this situation see Balancing Loop with Delay.
It is also possible that the structure that exists promotes an endless oscillation. For insights to this situation see Indecision.

Examples

The following examples are intended to provide some specific instances in which a balancing structure is the primary structure.