In this video Bill describes the difference between Value Adding and Waste and what should be done about activities that are not Value Adding but are still necessary for an organization to function.
Too often organizations are broken up into functional silos that are disjointed, rivalistic, and unable to effectively communicate with eachother. This is the opposite of Lean. Instead, businesses should be organized into Value Streams that are focused on their customers. Managing by Value Streams allows for the quickest flow of information and materials possible with each Value Stream establishing its own performance metrics based on that Value Stream's customer's definition of value.