The season is a capacity problem
Businesses tend to plan the festive quarter as a marketing exercise: campaigns, offers, decoration, advertising. Then the peak arrives and the constraint turns out to be entirely different. The phone rings more than anyone can answer, messages accumulate faster than they can be read, stock of the fast moving item runs out on day three, and the team works long days while a growing pile of enquiries receives no response at all.
That is a capacity problem, and capacity has to be arranged months in advance. The uncomfortable implication is that the most valuable festive planning work is unglamorous: stock commitments, staffing, response standards and a way of counting what is being missed.