The following diagram shows a representation of the value stream’s four main areas of focus:

It is important to realize that although Lean uses flow as a metaphor, that can be misleading in two ways:

• Work flows both ways to achieve quick feedback
• Development systems are more like networks than like a series of linear steps

The intention, however, is to realize that there is an order in which work takes place and that constraining any part of the stream slows everything down. Also, by looking at queues (think of reservoirs before a dam) one can see where these constraints exist.

When looking at this diagram therefore, it is important to recognize that it is just being used to illustrate the four main responsibilities within the value stream:

• Lean Portfolio Management: Deciding on the investments an organization is going to make and the strategies and initiatives are to manifest value from them
• Lean-Agile Product Management: how to take these initiatives and provide them to technology to implement them
• Technology: how to further refine the value to be realized and to implement it
• Release to realize value: it is important to set up releases to actually realize value – not merely get products deployed

While not shown on the diagram, there is a fifth aspect to the value stream – that is – it’s management. As Edwards Deming said – “A system must be managed. It will not manage itself. Left to themselves, components become selfish, competitive, independent profit centers, and thus destroy the system … The secret is cooperation between components toward the aim of the organization.”