Change management - necessary/desirable

When using NEC3 ECC, you should of course ideally starting from the position of having an outstanding Works Information, with the expectation that change should be fairly minimal once the contract is awarded. It is of course a good idea to lay down a few rules in respect of post contract change management for the ECC Project Manager (PM) to comply with, whether the PM comes from in-house or a consultancy.

Apart from key things like monetary thresholds, how about getting the PM to distinguish between necessary change and desirable change? Necessary change is just that, something that absolutely must be changed (because it's wrong, or ambiguous, or inconsistent, or was missed off, and so on). Desirable change is where the PM considers it is not necessary, just would be better (aesthetics, quality, longer life, easier to maintain, and so on). This would at least give a client the chance of distinguishing between must have and nice to have changes.