A delta is expressed as change, not as a score. It covers what the institution would newly be doing, which environments it would newly be in, which permissions or structures the activity would depend on, and what would have to be true operationally for the position to hold.
Deltas are comparable. Two candidate designs for the same objective produce two deltas, and management can choose between them on that basis — including choosing the design with the smaller delta for the same commercial outcome.
A delta of zero is a real and useful result: it means the decision does not move the institution's position, which is itself worth evidencing.