It's survival of the fittest out there. If you only practiced one of the three, your body would never have the all-around stamina to endure the grueling competition. While lean manufacturing is a valid piece of the puzzle, true lean business thinking goes much further than that. Lean is a system. It incorporates everything in the organization.
Companies focus too much on little islands of improvement.
They don't think about how all this stuff integrates together in the long term. They're doing a piece of lean, but to really leverage all the activities into a lean enterprise is a much bigger picture than most of them consider. Lean Business Workgroup. You have to look at the way you take an order, the way you process an order, the way you purchase material, the way you do the manufacturing of it, the way you ship it. The standard concept of lean manufacturing is to make each work center more productive by eliminating steps and by having the right material in the right place in the right quantities when it's needed.