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. Value stream mapping is typically used in Lean, it differs from the process mapping of Six Sigma in four ways:

1) It gathers and displays a far broader range of information than a typical process map.
2) It tends to be at a higher level (5-10 boxes) than many process maps.
3) It tends to be used at a broader level, i.e. from receiving of raw material to delivery of finished goods.
4) It tends to be used to identify where to focus future projects, subprojects, and/or kaizen events.

A value stream map (AKA end-to-end system 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 insight 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 it map the information flow that enables the process to occur.