The second of the five-lean-principles: identify the entire value stream for each product or service family. After defining value, the next step is to map every action required to bring a specific product from concept to customer — then classify each step as value-creating, non-value-creating-but-necessary, or pure waste.
The Concept
james-p-womack and daniel-t-jones defined the value stream as "the set of all the specific actions required to bring a specific product through the three critical management tasks of any business: the problem-solving task, the information management task, and the physical transformation task" (lean-thinking, 1996).
This is broader than a manufacturing process map. It includes design, order processing, scheduling, and delivery — the full arc from concept to cash. The value stream concept forces organizations to see across functional silos (engineering, manufacturing, logistics, sales) and across organizational boundaries (suppliers, the company, distributors, customers).
What Changed in Translation
taiichi-ohno and toyota-motor-corporation managed supplier relationships and production flow within their specific industrial network — the Toyota keiretsu. The value stream concept abstracts this into a generic analytical tool applicable to any product in any industry. What Toyota did through decades of supplier development, Womack and Jones propose organizations can begin to do through mapping.
The abstraction gains portability but loses the relational depth of Toyota's actual supplier management. Toyota's value streams were embedded in long-term partnerships, shared investment, and mutual commitment. The value stream concept, as a map, can be drawn without any of those relational foundations.
Value Stream Mapping
The value stream principle's most important operational expression is value-stream-mapping, the diagnostic tool developed by mike-rother and john-shook in learning-to-see (1999). seeing-the-whole (2002) extended the mapping technique from single-facility to cross-organizational value streams. These workbooks made the abstract principle into a concrete practice.