First of all, let us clarify what I mean by planning purity. Planning purity in my understanding is clear and ideal planning in which quarter tasks fit very evenly into months, those in turn into weeks, and those already into days. All tasks are completed and closed on time, and there are no loose ends or carryovers.
Maintaining planning purity is very hard and far from always necessary. The lower you go toward implementation, the more messy notes may appear. There is no escaping this — such are the realities of life: something spontaneous will always appear that affects current tasks for the week or, in individual cases, even tasks (goals) of sprints.
The absence of planning purity can also show itself at the upper level. For example, when planning a quarter I may see that a given task most likely does not fit or, say, is perhaps not so important right now. In that case when distributing tasks across months that task may still hang in the air for a couple of days until the quarter is precisely "approved." That way I have time to think where to push it and whether it needs to be pushed anywhere at all, or perhaps I do not need to do it now. Or, for example, there were situations when I did not manage to complete a task in a month at all, and then it was moved to the next month, or worse — temporarily put on pause, and I finished it only a month later.
Perhaps planning purity can be achieved if in year planning you set only a couple of goals, but with a large number (as I have) ideal planning is hardly possible. It is rather about situational planning, constant shuffling of tasks at lower levels, as well as temporary pauses or transfers at upper levels. On the other hand, although I wrote that you should not strive for ideal planning, you should also not create chaos in the goals and tasks you have mapped out for the year. If we are talking about adjustments and reshuffling of goals and tasks, at the upper planning level I would recommend limiting yourself to 5–7% adjustments of goals, and at the lower level — 7–10% of the tasks planned for the chosen time interval.
