I grew up in central Florida, where snow was rare. When it happens, it usually means a few small flakes. But now I live in Dallas, Texas where we have been hunkered down for four days after ice and sleet closed our roads. (If you are from “up north” where you have real winter storms, don’t laugh just yet, but hang with me while I make a point).
This local article was talking about the lingering effects of the storm including anticipated potholes: http://ireader.olivesoftware.com/Olive/iReader/StarTelegramPress/SharedArticle.ashx?document=FWST%5C2013%5C12%5C10&article=Ar00702.
The article also answered questions about potential construction delays on major road projects in the area, since no work has been done for several days.
Of course there is no overall schedule impact because the schedule has “snow days” built in, to accommodate for some reasonable amount of bad weather. So far we have had fewer bad weather days than anticipated, and these projects are on schedule if not slightly ahead.
But what about construction in Florida? What about installing a new production line inside a factory in Nevada? What about a new product rollout in New Mexico? Do those projects need to schedule “snow days?”
The simple answer is yes, though you won’t call it snow days.
Call it “schedule buffer” or call it whatever you need to for management to understand it. Then manage those days as a precious commodity.
If instead you schedule every task as though there will be no hiccup, no miscommunication, no delay in performance, if you schedule assuming “perfection” as it were, you are doomed to fail. Perfection doesn’t exist on this earth, at least not in any of our projects.
You could just inflate the time estimate for every task. But then you won’t manage that time. Three quarters through your project, you may have squandered most of this precious commodity of time, just when you need it most. Better if these days are managed separately, much like you would manage the contingency account in your cost budget.
What we are talking about is a “schedule contingency,” to be guarded, managed, and where possible, clawed back if used, by seeking efficiencies elsewhere. Just as a cost contingency can help you manage the inevitable, while completing the project on budget, a schedule contingency can help you manage the inevitable, while completing the project on time.