There are scenarios when it gets difficult to measure a particular metric within a Key Result. This can happen when you have a binary outcome to track. In such cases, one uses a Milestone Key Result which is essentially a critical Initiative raised to the level of a KR. In order to ensure there is progress towards the Objective, such milestone KRs must satisfy two conditions: 1. It must either help in creating a metric or a baseline; 2. It must convert to a robust, progressive Key Result (once the baseline has been achieved).