Traditional Six Sigma Mantra
Six Sigma has always been about reducing variation. Traditional Six Sigma strove to reduce process variation and its success at doing so has been well documented. Traditional Design for Six Sigma (DFSS) strove to utilize quality tools in the design processes to yield products that meet customer expectations. DFSS successes have been less prevalent, which might be the case because it can be more difficult to quantify and demonstrate veritable results.
Criticisms of Traditional Six Sigma
The critics of traditional six sigma often cry: sure you've reduced process errors, but how has that influenced the customer perceptions of product/service value? Sometimes the influence on customer perceptions are direct as in the case of reductions in call center wait times or paper work cycle time (which makes the organization more responsive to customer requests), but is the customer really receiving more value when callers are routed through a complex call filtering system for the sole purpose of reducing variation of in-call handing times?
Then there's DFSS, with tools such as the Voice of the Customer (VOC), Quality Function Deployment (QFD), Analytical Hierarchical Process (AHP), etc. Well...., these tools as proposed and traditionally used are good in theory, but..., well..., they're difficult to use in practice and often collapse under their own weight, which ends up forcing managers to shoot from the hip anyway.
Value Driven Six Sigma
The mantra of Value Driven Product Management is to use product value, product cost, and pace of innovation to guide variation reduction decision making. Value Driven Six Sigma and Value Driven DFSS looks at variation reduction through a new lens: reduce process and product variation so long as the result is positive net-value creation. The net-value of any product management decision is the change in product value minus the change in product cost. The third fundamental metric of product management is pace of innovation, which is a measure of how fast the product/process changes can be made.
Design for Six Sigma as Strategic Experimentation