Value stream mapping is a lean manufacturing technique used to analyze the flow of materials and information required to bring a product or service to a consumer. This process was successfully implemented in the manufacturing industry by Toyota and has been mapped to software development too. Does software development follow the same path as manufacturing?
Alan Cyment mentioned that he was disappointed with the value stream mapping for software development. He would rather consider it to be an oxymoron. According to Alan,
Yes, process must be optimized. Yes, it’s fine to try and find waste, so that you can eliminate it. Yes, you can write down what you did , especially if writing it down helps you find useless steps. But it is simply nonsense to ask a Scrum team to describe the process they follow every time they develop software. The whole point of this thing game we play is that we will adapt our process on the go.
Alan mentioned that though the process is good for manufacturing, it cannot be applied in the same sense to software.
According to Kaizen Institute, you can identify a true value stream where repetitive actions take place. They mentioned scenarios like letter traveling through the post office, a piece of steel that will be converted to a refrigerator casing, a patient flowing through a hospital, an insurance form traveling through the approval process, or a purchase order traveling through the requisition process. They mentioned that value stream mapping cannot and should not be applied to something like a product development process.
The steps taken to produce a specification/design are rarely sequential. There's Step 1, Step 2, Step 1, back to Step 3, Step 1, etc... There is no solid dependency - finish 1 step and start the next. For example, you might not know all of the customer requirements before you start your design work - it's a very iterative process. The output is often knowledge. Trying to Map all the nuances in Product Development using a traditional VS Map could drive you crazy, and you'll never get it right!
Jurgen Appelo further suggested that value stream might be a bad metaphor altogether. According to Jurgen, value stream suggests a flow of value from A to B in one direction. However, this is rarely the case. According to him, more than a value stream where one is working towards creating value for another, it is a collaboration of different stakeholders to create value for themselves and hence a value network.
It is bad to portray a business as a factory around a value stream. There is no “stream of value” flowing through a business in one direction. The value stream metaphor is misleading. A business is a network of stakeholders all creating value with each other. All stakeholders (shareholders, employees, customers, suppliers, and communities) are trying to generate value for themselves from their collaboration with others. Your business is not a value stream. It is a value network.
Value stream mapping is strongly encouraged by Mary and Tom Poppendieck, who recommend that people start with a value stream map to find out waste in their process. Though, there have been several success stories where teams have utilized the value stream concept, however, there are also questions on whether it can be truly applied to software development which is by definition Agile, embraces change and the process itself might undergo a change on the basis of inputs received and the value network generated.
By continuing to think in manufacturing metaphors we will continue to bind our thinking to manufacturing practices. Think differently.
