Volgens Jim Womack en Daniel Jones is het de taak van het management "[to] understand and improve the underlying value-creating process that suppliers share with their customers". In het boek Seeing the whole value stream beschrijven zij wat ze verstaan onder de waardestroom:

Value-stream mapping

An (extended) value stream is all of the action - both value-creatin and wasteful - required to bring a product from raw materials into the arms of the customer.

The relevant actions to be mapped consists of two flows: (a) orders traveling upstream from the customer (or from the sales department when forecasts substitute for confirmed orders) and (b) products coming down the value from raw materials to the customers. Together these constitue a closed circuit of demand and response.

Value-stream mapping is the process of directly observing the flows of information and materials as they now occur, summarizing them visually, and then envsioning a future state with much better performance.

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Selecting a product family

A key objective of value-stream mapping is to disaggregate operations to the level of specific products, where they can be more easily acted on by managers. To do this you need to start at the furthest point downstream (toward the customer) to be mapped and to define product families at that point. Typically a product family will include a group of product variants passing through similar processing steps and using commong equipment just prior to shipment to the customer.

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Note that the same product family may be supplied to a numer of different end customers and have cosmetic differences causing the casual observer to overlook product commonality. Nevertheless from the standpoint of the firm or facility at the downstream end of the map, the product is clearly a family.

Bron: Seeing the whole value stream, Jim Womack & Daniel Jones