“Measure what can be measured and make measurable that which cannot be measured.”
—attributed to Galileo Galilei
This notion that measurements should not be done for things that are not measurable is of course nonsense. If you're spending other people money, you'd better have an answer to how much, when, and will this work in units of measure meaningful to those decision makers.
So if you have planned work that has no measures of performance, you'll never be able to connect the cost with the value.