Back when I was solo consulting and not inside the sausage factory I would provide cost ranges to clients who wanted fixed price (vs hourly). If they wanted a firm price they got the +3-sigma estimate. After doing that for a few years and successfully coming in within budget but not always on the timeline people were expecting I split it into separate estimate ranges for both cost and schedule. It took some time to really nail down how many billable hours there would actually be in a week, which is why cost and calendar had to be decoupled.
I do still laugh about the fact that I could take a complex problem and break it down with hour estimates well enough to not end up being significantly over or under at the project level but then struggled really hard at figuring out how many hours there actually were in a day to put the calendar together. There’s always things that pop up that rob calendar time and virtually never things that free up calendar time.
I do still laugh about the fact that I could take a complex problem and break it down with hour estimates well enough to not end up being significantly over or under at the project level but then struggled really hard at figuring out how many hours there actually were in a day to put the calendar together. There’s always things that pop up that rob calendar time and virtually never things that free up calendar time.