Answered by Robert Halligan
One of the criteria for a good MOE (not requirement) is that it is substantially independently valued as an outcome. The incidence of highly coupled MOEs is not frequent. When this does occur, it is inevitable for one of two reasons:
- the two MOEs are contributors to the real MOE. An example would be Reliability and Maintainability, where the real concern is Availability, e.g. with a bank and an ATM; or
- there is double-counting in the MOEs, e.g. Life Cycle Cost and Development Cost.
The usual number of MOEs necessary to capture most of the tradeable value beyond requirements is few, from 5 to 15 or so. I wonder if the complexity of solution relationships is being mistaken for complexity of value relationships.