Value stream mapping is a paper and pencil tool that helps you to see and understand the flow of material and information as a product or service makes its way through the value stream.
A value stream map takes into account not only the activity of the product, but the management and information systems that support the basic process. This is especially helpful when working to reduce cycle time, because you gain insights into the decision making flow in addition to the process flow. It is actually a Lean tool.
The basic idea is to first map your process, then above the map the information flow that enables the process to occur.