Parkinson's Law states that "work expands to fill the time available for its completion." In many cases, this law also manifests itself as "estimates of work expand to the available (or desired) level resources."

In a related publication, Parkinson related his experience with government bureaucracies and observed that a committee was always at it's largest when its influence was at its smallest. This became known as the Coefficient of Inefficiency, and was described in detail in a chapter titled Comitology in his book Parkinson's Law: The pursuit or progress.

Parkinson's law is very real and can create a tremendous amount of waste on projects and programs if not dealt with.

The following are simple ways to help combat Parkinson's Law:

1. Schedules and deadlines should be very aggressive. Seek to get more work done than is actually possible. This said, you need to be willing to accept less than what you are asking for.
2. Expose the highly critical tasks and prioritize them to the front.
3. Break tasks down into short, measurable increments. Track them at the 8 - 24 hour level.
4. Track metrics on how well tasks are executed, by individual (to learn capabilities, not to chastise).
5. Maintain an accurate 'task backlog' by skill. This is a queue of sorts and it needs to be kept full.

In short, maintain high pressure, short deadline task lists and you will have gone a long way to combat the effects of Parkinson's Law.

Other Resources
Shine With Grace blog
Focused Performance