Leading Six Sigma [the broken link was removed]: Launching the Initiative by Roger W. Hoerl and Ronald D. Snee. An excerpt, of a chapter of their book, Leading Six Sigma: A Step-by-Step Guide Based on Experience with GE and Other Six Sigma Companies discussing the deployment process for Six Sigma.
The project must be tied to the bottom line in some way. The project scope should be for improvements that are attainable in the four to six month time frame. An unrealistic scope (often referred to as a “boiling the ocean” project) is probably the most commonly encountered cause of project failure. Projects that are not connected to business priorities or that have too many objectives also need further refinement. Projects with an “identified solution” should be handled by a project manager instead of Six Sigma, or as mentioned earlier, be redefined to omit the specified solution in favor of allowing the Six Sigma methodology to identify the best solution.