From lean tools to lean management (link broken by site so I removed it) by Jim Womack:
Please understand: Lean tools are great. We all need to master and deploy them, and our efforts of the last 15 years to do so are not wasted. But just as a carpenter needs a vision of what to build in order to get the full benefit of a hammer, we need a clear vision of our organizational objectives and better management methods before we pick up our lean tools.
Exactly right, as usual.