For value, the question is: “Does the system produce actual output benefits equal to or greater than its costs?”
B > C
If the answer is situationally negative, then the next question is: “What change is required (delta) in the output to make its benefits equal to or greater than the cost of producing them?”
ΔB ⇒ B > C
-AND/OR-
ΔC ⇒ B > C