Jim, in his comment on Intuition is Not Enough for Knowing About the Project Portfolio, said:

I am having trouble with the definition of the word “value” in this context. Do you mean showing progress, as in earned value, or value to the customer, such as in ROI or payback period? Value has become a loaded word. Please define your terms.

To me, value is some visible form of progress. I prefer working product. I can live with a demo. I can live with a prototype. In some very small number of organizations, I can briefly live with a document. A document ceases to be visible progress after a very small period of time, such as a few days, maybe a week. Demos and prototypes also lose their value over time, if they do not become working product.

Managers can’t make good decisions about the portfolio if they can’t see visible progress, so they can tell if the money they’ve spent is worth the time they’ve invested.

If I really knew how to calculate ROI (and not make it be a number I can just make work), I would use ROI. But that’s a bigger rant for another time.