“Planning is more important than the plan”
One should not treat a business plan, a strategic plan, or whatever plan as the organization’s holy bible because chances are that once it has been printed, it is already obsolete. A change in any of the factors that were considered in making the plan will automatically render it inaccurate. Sticking with it regardless of that fact is one way of leading the organization to failure.
This also happens to be aligned with how the Japanese think: The quality of the product depends largely on the quality of the process that created that product. If not enough resources is invested in the planning process, chances are that the plan, no matter how nicely presented, will be useless.
An organization then, should always be mindful of its planning ability first. The quality of the plan will normally just follow.