A discussion on how to model the value created/added by value stream stages

On Section 7.3.2 is stated: "Value streams can be a composition or aggregation of value-adding activities. These are also modeled with the value stream element and known as value (stream) stages. Each of which creates and adds incremental value from one stage to the next. These stages are typically related using flow relationships to model the flow of value between them."

The example 22 shows a value stream with value stream stages, and (following directions drawn from the BizBOK Guide[18]) associates the value created/added to the flow that connects one stage to the other. Analysing this exemple, it presents some subtle issues:

• the influence relationship (it might be a realization relationship as well) to the outcome should originate on the entire value stream, not on the last value stage, to model that the entire value stream actually contributes do/realizes the outcome.
• the last value stream stage isn't followed by a flow relationship. So, we end up with a situation where some values are related to flows and the last one to an influence/realization.

Therefore, I propose some changes on the way a value stream should be modeled: 1 - use the Influence relationship to link each value stage to the value it creates/adds (association is a weaker option here) 2 - as already mentioned, link the whole value stream to the outcome, using Influence ou Realization relationships

The proposed example might become:

Eventualy an overall value migth aggregate the stage values, and be associated to the outcome.