A marketing measurement plan, outlines the objective of the marketing activity, the tangible things that need to be measured, the relevant metrics for the objective, the tools used and finally the workflow to capture, QA and surface that data so it is actionable.
Adopted by media & enterprise teams, setting a measurement plan upfront helps ensure success but also puts rigor in to the marketing activity. It’s almost like a mini check in.
Where they go wrong, is if this is created as a final step, rather than a collaborative process as the marketing plan is created. This works to inform and educate the wider team on what can be measured and how. Which ultimately may mean adjustments in execution.