Productivity and pornography
10/29/2010 3:36 PM EDT
"We must increase our IC development productivity!" is the persistent invocation from semiconductor industry executives, and it's getting louder by the day. It's not surprising. Yet when I ask the question, "What do you mean by productivity?," executives and R&D managers often give vague answers. Few seem to have a firm grasp of the definition, other than saying "we need to finish projects on schedule, reduce development cycle times and use fewer engineers." As a characterization of the benefits of boosting productivity, it's not a bad start.
It reminds me of U.S. Supreme Court Justice Potter Stewart's comment in a landmark First Amendment case in which he described the challenge of defining pornography: "Pornography is hard to define, but I know it when I see it." Maybe semiconductor executives are saying the same thing: "Increased productivity is hard to define, but I know it when I see it." Justice Stewart subsequently recanted, concluding that pornography can be indeed defined. So too can productivity.
As a starting point, consider the U.S. Department of Commerce (DoC)'s definition of manufacturing productivity: "Output divided by Labor-input." Output is the difference between the widget's selling price and the cost of materials comprising it. Labor-input is the effort expended on manufacturing it (in person-hours). The dimensions of manufacturing productivity are therefore: Dollars per person-hour.
We can use a similar approach to quantify IC development productivity: Output/Labor-input. However, Output must be a calculation of the design's complexity as opposed to value-add. That's because complexity is a measure of the development team's output. For the moment, let's assume we can calculate it—a challenge, but one that's definitely achievable.
Labor-input, the denominator, is the total effort the IC development team spends on the project from start to finish. The start milestone is "begin concept definition." The finish milestone is release-to-volume production. Consistent accounting from one project to the next is a must. Also, it's more reliable to use full-time equivalents (FTE's) instead of counting person-hours, where one person working full-time for a week is a an FTE, or a "person-week."
Adapting the DoC's mfg. productivity definition to IC development productivity yields a productivity metric whose dimensions are: Total IC development effort expended divided into the chip's design complexity (i.e. "Complexity/Effort"). The key question of course is how to accurately calculate design complexity?
Ronald Collett is president and CEO of Numetrics, which provides fact-based project planning and benchmarking software that improves IC development productivity and schedule predictability.