Managing your work flow can help create a "lean" and mean metal shop.
(The following is taken from Sheet Metal Made Lean and Clean: An Introduction to the Principles and Methods of Lean Production for Sheet Metal Shops.)
The second challenge in converting a shop to lean production is to make the work flow. There are a couple of questions to ask to determine if a "lean" work flow is appropriate for your shop. Are the things you are making going through the same sequence of operations time after time? If the way you are doing your work today is not repetitive, could it be made more repetitive by standardizing how the work is done?