Relaxation Time

The relaxation time of a system is the time it takes to return to equilibrium after a disturbance. When a disturbance hits a system, its effects ripple through the whole like the wake of a motorboat on a lake. The effects of the disturbance on the system are not necessarily in a direct ratio to the distance from the point of impact and the point affected (think of a picnic basket left at the water's edge when the motorboat speeds by). Generally speaking, **the larger and more complex the system, the longer the relaxation time** will be. **Relaxation time ranges** from almost instantaneous at the molecular level to a number of decades when a community has suffered a disaster.

Relaxation time becomes a serious problem for a system when the relaxation time is, on the whole, longer than the **time between disturbances**. Systems can only learn and adapt when they can recognize when they have returned to equilibrium. If the rate of disturbances overtakes relaxation time uncontrolled oscillation or a crisis pattern of response will occur and planning will be likely to be wrong or ineffectual. If the system cannot **recognize its state of equilibrium**, due to inadequate relaxation time it may not recognize when it is entering a region of instability which could result in catastrophe.

# SOURCE The term relaxation time first came into common usage in engineering and control theory. See also: Beer, S. (1975). Platform for Change. Chichester: John Wiley & Sons.

# EXAMPLES • waiting to introduce new materials and procedures until after the current ones have been tested • the time it takes for a product to regain its market share after a scare such as the Tylenol tampering case • the recovery time of an economy after a depression • the regrowth of a forest after a fire

# NON-EXAMPLES • the operation of a system such as waves in the ocean characterized by a pattern of dissipative structures where creation and destruction occur in a continuous cycle • changing chief executive officers before the results of their initiatives have occurred

# PROBABLE ERROR • **Underestimating** relaxation time, • **Attributing system failure** to adapt to lack of resources or leadership instead of insufficient relaxation time, • Inability to **distinguish normal oscillation from uncontrolled oscillation**.