Product life cycles continue to shrink in "fast" industries like fashion and personal computers, where new products roll out the door every few months. Even "slow" industries like steel have quickened their pace. Speed is of the essence—but so are quality and cost. Companies in all sectors know they must deliver on all three dimensions simultaneously.

Yet world-class product development is still by far the exception. Even the most disciplined and creative product development processes can be plagued by schedule slippages, "firefighting," and inferior quality. Often, the problem is a failure to consider product development as a dynamic whole. Managers try to improve performance by breaking the process apart.

But isolated improvement efforts (such as the best practice themes listed in Exhibit 1) can actually have a negative effect on performance when they are implemented without regard to the multiple interrelationships that drive the product development process. Setting aggressive commercialization schedules, for example, often has just the opposite effect of what was intended: namely, longer delays with lower quality. And many other cherished management beliefs, such as "lean and mean" staffing, can also inadvertently contribute to product development problems.

Consider...