## TL;DR
Teaches you about a very useful tool for strategic planning and change, but that's the limit, you need to know Lean principles and how to implement them by yourself, it assumes you got a handle on that, or point you to sources, but that's it. It doesn't diminish the value of the book, but a real implementation will require a lot more research and investment, the execution part at the end of the mapping is the real challenge.
## Opinion
The authors propose Value Stream Mapping as a tool to plan and guide strategic changes for a company, the basic methodology consists of a 3-day workshop split into: current state mapping, future state design, coming up with a transformation plan, one day for each. The workshop participants should be high level executives or people with power to approve and oversee the execution of big strategic changes, middle managers that like to talk and do politics but cannot change anything without permission from above aren't welcome. Before the actual mapping starts the organizers need to scope which value stream will be worked on and gather preliminary data that will support the process, then the mapping starts for real.
The current state mapping on day one is pretty self explanatory, but the way it's done is interesting, because it isn't a white-boarding session with people who have no contact with the real work, instead it consists of people "walking the gemba" (visiting where the work is done), seeing and talking with the folks that actually do the work. After that they retreat to a room to draw what they saw, using a specific notation (which is pretty simple) and adding some metrics to it. With the diagram they have a better understanding of the process, their lead time, process time and "quality", and they go back to the gemba to verify if it's accurate. After that the current state should be close enough to reality and people can share a similar understanding of the situation, share it with people that will support the changes and then go to sleep.
On day two they revisit the scope and the current state and discuss what changes should be made to the current state to achieve the pre-defined goals. This might include removing or adding processes, change the way inspections are made, train people in a different way, etc, there's a suggested list of traditional changes but they aren't very prescriptive, because each situation is different. Once the changes are decided upon the group create a future state map that will reflect the value stream after the changes are made, and add the target metrics that they expect with the new flow. They might go back to the gemba to review it and then show the result for supporting collaborators, and that's the end of day two.
On day three they will go back to the future state map and document the list of changes they expect to make, assigning owners, defining timelines but NOT going into details of "how" they will be implemented, the implementation part is up to the people that will actually do the work, the mapping exercise will provide them with the goals and a vision of how their changes will impact the system. After that the mapping exercise is finished.
As the authors say, after the mapping is when the rubber meets the road, and while they have some prescriptions on how to approach the execution, they are far from prescriptive, they leave it as an exercise for the readers, and that's the "let down" of the book, because the planning part is "simple", if insightful and practical, but I fear that the execution is the real problem. The authors aren't naive and they are aware of this "limitation", and offer some references throughout the book to guide people to learn how to do the rest, but that's it.
The mapping is a good tool, but it's pretty much it, you could use a lot of other planning tools to achieve similar goals, the upside of the book is that they try to persuade the reader to expand their Lean view towards the rest of the organization instead of stopping at the rituals, but they cannot fix things like stupid org charts, disempowered employees, lots of politics and silos, etc. They don't see it as only a tool, but I cannot in good faith say it's more than that.
Read the book to learn the tool and be inspired, but be prepared to research a lot to actually implement it.
## Book notes
### Value
* Value stream mapping is a discovery activity
* Shared understanding of the work, reducing differences in perception, therefore reducing conflicts
* Consensus building around problems
* High level abstraction of the work makes it easier to understand
* High level changes are strategic changes, they more impact than process/tactical ones
* It's a visual storyboard of how work actually gets done
* Helps to eliminate waste work and minimize value-enabling work, focusing on value-added work
### Limitations
* Doesn't fix micro-level process problems
* Focus on strategic changes, if strategy is set its value is limited to understanding
* The implementation part is left as an exercise to the reader
### Observations
* Lots of references to traditional hierarchical structures
* Apparently the focus is to use value stream mapping as a tool for highest ranking executives
* How to identifies the value streams? Apparently they assume it's just figuring out what are the requests and move from there, or it's explained on another chapter
* They also assume that you already know the value proposition of the product and desires of the consumers, they won't help you figure that out
* How to find the right balance between macro and micro level detail? Apparently the "solution" is to get experience
* 3 types of work:
* Value-adding
* Value-enabling (necessary non-value-adding)
* Waste (unnecessary non-value-adding)
* 8 different types of waste
* Transport – Moving people, products & information
* Inventory – Storing parts, pieces, documentation ahead of requirements
* Motion – Bending, turning, reaching, lifting
* Waiting – For parts, information, instructions, equipment
* Over production – Making more than is IMMEDIATELY required
* Over processing – Tighter tolerances or higher grade materials than are necessary
* Defects – Rework, scrap, incorrect documentation
* Skills – Under utilizing capabilities, delegating tasks with inadequate training
* Highlighting the systems used in the process and how the information flow across them seems to be a critical part of the mapping process, probably a lot of insights can be gained from this