Lured by the prospect of major costs savings and productivity improvements, executives eagerly proceed with Lean or Six Sigma projects. The reality, however, is that most Lean implementations fail to produce the desired results, especially in white collar environments. In fact, I am frequently approached for advice from disheartened executives who have overseen a failed Lean implementation. These executives typically saw organizational performance improve throughout the Lean project, but watched with disappointment as process improvements declined, as performance stagnated (in some cases even regressed), and as cost slowly crept back up soon after project completion. After 25 years of experience in this field, I suggest that there are three reasons why Lean projects in white collar environments fail to produce the desired results.