Six Sigma's too slow!

This is an excerpt from an email I received recently from someone engaged in a Six Sigma project in a large British organisation;

"Six sigma is alive and well - but takes too long. I prefer shorter projects. Our project on xxxxx is a good example. We started it Jan 04 (it's now April 05) - we are in the middle of Improve phase!. As there has been so many changes to the xxxx plan since we started if we fix what was in our original scope we may not see a great improvement as something else now has become broken. And new things can not be added into the project at this stage - they must be treated as a new project entirely. It is not flexible to reflect the changing nature of (our service)