The Value Stream Impedance (VSI) Scorecard is a qualitative method of determining if a change to your system will be an improvement or not.It is used to predict whether a speculated “to be” state will be an improvement over the current “as is” state. Essentially it looks to see if the resistance to flow will increase or decrease. The VSI Scorecard should be used as a heuristic as change in complex systems is not predictable although it can follow patterns.
When learning how to drive a car, one of the first things you must learn is “how well are you keeping the car where it should be.” An aspect of product/IT development is that you need an understanding of the resistance you are facing – that is, are you one the road. By lowering this resistance you will get more from your efforts. This is the purpose of the value stream impedance scorecard.
Systems-thinking tells us that most of the errors people make are due to the system instead of the individuals. That is, good people make mistakes significantly more often in bad systems than they do in good systems. For examples, testers who are located away from the development group that are given their work in big batches will not do as good a job testing as testers embedded with the development group. This does not mean that people aren’t important. It actually means just the opposite because people are important we don’t want to waste their time in bad systems and we need them to improve their current systems.
The approach therefore needs to be:
This article describes the Value Stream Impedance Scorecard
The Value Stream Impedance Scorecard
The Value Stream Impedance Scorecard is a way of assessing how much resistance to identifying, creating and realizing value (both business and customer) based on observing the system in which you are working, the work being put into the system, and how people are collaborating. There is great evidence to support the efficacy of this approach. Just as important, Lean-thinking provides an effective model for predicting what would lower this resistance. This enables us to make changes with confidence that they will be effective.
The contention is that the more impedance, the more extra work that is created. The key word here is extra. In other words, not only does the system slow us down, it creates additional, unneeded, work to be done as well. Examples of this is the thrashing that often takes place when software developed by different teams are integrated.
The Value Stream Impedance Scorecard is a set of quantitative measures of the resistance to work within a value stream. These measures include how work to be done is selected, sized and sequenced, the organizational structure of the people doing the work and the way the people do the work. These measures work together to help you drive improvements to lower the resistance.
The Value Stream Impedance Scorecard highlights factors that are out of line or are causing resistance. To address resistance, you conduct experiments to address one of the factors and then examine the results in the scorecard.
The Value Stream Impedance Scorecard and Systems-thinking
The Value Stream Impedance Scorecard takes a systems-thinking view to the resistance to work within a value stream. The set of quantitative measures are intertwined in a strong positive loop when improvements are made and a strong negative loop when degradations are made. For example, increasing the number of items in play will have adverse effects on the other components of the scorecard.
This is one reason that Lean-Thinking is so useful. There are seldom tradeoffs between its core mantras. This enables even a qualitative measure of the VSI of a system to provide a useful indicator of the challenges that will be encountered in a value stream. Understanding what causes a high VSI enables us to take corrective action to lower it.
The initial ideas of the VSI grew out recognizing that virtually all of the pioneering ideas that Net Objectives has created over the years were created to improve flow. Typically, we saw a challenge and understood the cause of the challenge was violating some Lean principle. We would come up with different ideas and those that reduced resistance to flow virtually always resulted in improvements.
Components of the Value Stream Impedance Scorecard
The Value Stream Impedance Scorecard is an attempt to quantify the challenges of a current value stream in a holistic way.
Here are the factors in the scorecard.
Exploring the Value Stream Impedance Scorecard
Consider each of these factors and what they might tell you.
Using the scorecard to improve value stream impedance
You can improve value stream impedance by taking steps to reduce those structures, management, workflows and anything else that contributes to them. Here is a list of actions to take that can almost always lower value stream impedance.
Size, priority and amount of work
How teams are organized, geographically located, and who they report to
The sequence in which work is done
Work level inside the team
Increasing the following will decrease the VSI within the system
Pay down your technical debt
All of the above will increase positive feedback loops which will lower the amount of induced work.