When we used to work from planning statements like goals and targets, we would assume when we would achieve it, considering our incorrect estimates as failures.
When we work from questions, we don't operate from assumptions. We do make preliminary decisions on how long we're going to work on our questions in order.
The more Clarity questions of what we need to discover and decide we have, the more likely it becomes that we will be agile in both the order and durations of our Dreaming questions of what kind of success and progress we want to see possible. Depending on what we learn from each question, we can adjust how long we will work on any question guiding our path.
How long we're going to work on any question depends on a mix of variables including how long things actually take, how many resources we have available and what else we're doing with our time. As these variables shift, so might our sense of how long we're going so spend on any of our questions.
We measure success by how much we can get done in the time we take on any of our most important questions.