The length of time for any operation to be completed from the start.  In the new product development sense, it is the length of time to develop a new product from an early initial idea for a new product to initial market sales.  Precise definitions of the start and end point vary from one company to another, and may vary from one project to another within the company. 

Generally considered the time from idea selection to commercial launch.

For additional NPD terms and definitions, click here.