My experience with Value Stream Maps

All lean tools have a purpose. Some tools like '5 Why' and '5 S' are straightforward and perhaps deceptively simple. Other tools like 'Fishbone' diagrams have a process behind them that is generally misunderstood. When done poorly, that second set of documents come into fashion in an organization and then go out of fashion without much staying power.

I'm not an advocate for so rigidly following the tool steps that we lose the communication value for a diagram. If the conversation gets caught up in the rules of 'how to' do the diagram right, something is wrong. But I also know that tools get developed for a purpose and there is great value in using the right tool in an appropriate way. As an ordinary life example, I may have a choice of tools in cutting down a tree. A hatchet, an ax, and a chainsaw can all get the job done in theory. Given a particular tree in a particular place, some tools will work better than others. Likely, one is probably the best choice for that particular tree. Each tool has its own set of safety precautions (how to use it) that need to be understood.

Value Stream maps have a very defined process that sometimes scares people away. The icons are set, and they each mean something specific. The formulas are set and are interconnected. The story is told the same way every time. This one document tells the full story of the transformation from raw materials (or ideas) into products in the customer's hands. It's adaptable to any business model but consistent in its presentation.

Here's how I've used them. It was worth the effort.

We would quarterly, usually 2/3 of the way through the quarter, take some time to walk and map the value stream. We used the icons properly and we calculated the formulas. This gave us a chance to measure the improvements from the past quarter, reflect, and prioritize. It then gave us a few weeks to queue up the discussions on what needed to happen in the next quarter. Sometimes we'd need to do some investigation before we were ready to take action, and we'd note that on the map to dig into further. The places we chose to improve, we addressed with other lean tools, most commonly using the A3 process, but frequently we also used glass wall metrics, focused gemba walks, fishbone diagrams, 5Why and Standard Work to support that work.

Of all the tools in the toolbox it was the Value Stream maps that best allowed us to see where to focus, and what kind of impact to expect. Over time, they also helped us to see actual impact we had made, and to document that we had reached and sustained our target improvement state. A side benefit is that it is easier to bring others (especially outsiders to the processes) up to speed when using a common tool and common language. Value Stream maps can be that tool and provide that language.

For more info, I'd point you to lean.org, the Karen Martin Training Group, or works by Michael Balle