Six Sigma, Innovation, and Usability

This week's (June 11, 2007) Business Week cover story is about how Six Sigma "almost smothered" 3M's culture of innovation. The gist of the story is that 3M's attempt to use Six Sigma in every corner of its operations, including R&D, caused innovation to become more incremental, more safe, and more saddled with administrative overhead. Consequently, higher risk programs weren't pursued and 3M has slipped markedly in measures of innovation, such as the proportion of revenues coming from recently developed products.

Having been through a Six Sigma transformation at a large organization, I have a few thoughts on this.

First, it seems to me that user experience is one of the most important and least appreciated aspects of quality. As a proponent of applying more structured methods to user requirements and usability assessment, I think that formal user requirements methods and structured usability testing fit right in with the spirit of Six Sigma and other quality programs. If Six Sigma, for example, causes an organization to move from focus groups to more effective human performance-based measures of usability, I'm all for it. I hope that anyone advocating for Six Sigma within an organization will recognize that user experience and usability are key aspects of quality and deserve the rigor and emphasis traditionally paid to engineering and manufacturing.

Second, I think that everyone should learn something about statistics. I think that some understanding of probability and statistics is actually necessary in order to not only work effectively, but also to make informed decisions in most aspects of life, including voting. When an organization adopts Six Sigma and makes everyone learn the basics of statistical analysis, everyone benefits, including society at large.

However, no program dedicated to process improvement should itself become a process impediment, and the indiscriminant application of Six Sigma to all parts of an organization has a lot of potential to do just that. It's well understood that many of the most profitable break-through products come from serendipitous discoveries enabled by exploratory research that may not be undertaken in a risk-averse, highly controlled environment. This is what the Business Week article focuses on.

To me, the benefits and drawbacks of Six Sigma all stem from the same source: the fact that Six Sigma tries to substitute objectivity for subjectivity and data for intuition wherever possible. I think this is both useful and appropriate in some applications, such as administration, logistics, and manufacturing, but not so much in R&D. Research and design, particularly the exploratory types that lead to breakthrough products, depend to a large extent on subjectivity and intuition and are easily stifled by processes that seek to drive them out.

Furthermore, even where it's useful and appropriate, Six Sigma can still fall down because it's very susceptible to garbage-in/garbage-out. In Design for Six Sigma, for example, people often have to enter ratings of competitive position and other market environment factors into an analysis process, and these form the basis for subsequent decisions. Many of these factors can't be directly quantified or measured and must necessarily be subjectively estimated. Lengthy analysis processes can often include chains of subjective judgments, and small errors in early steps can compound into much larger errors at the end. It very easy, in Six Sigma, to end up with a product that looks like fact or data but is actually largely fiction, because of the use of formal methods to force subjective products into an apparently objective framework.

The bottom line, I think, is that Six Sigma and other quality programs can be very useful and productive if used within their valid limits, but can be highly counterproductive otherwise.