We always try to do our best, but particularly within the context of the PCO's complex environment, certainty is a bit elusive at times. We do take into account the behaviour of the organization more and more, and, as you say, the past historical context, particularly when we adapt quickly to new initiatives that are added mid-year. If a new priority arises in June, for instance, that would require the organization to adapt.
On April 25th, 2013. See this statement in context.