Project work estimation has three components: the initial first cut, commonly known as a SWAG (scientific wild-ass guess), tracking the estimate against the actual numbers, and using the schedule to see what’s happening in your project.
If you’ve been assigned project estimates, or if your project estimates aren’t particularly close to reality, don’t fret.
Try this to make and learn about your estimates.
If you’re a project manager, you probably try to estimate the work at the beginning of the project, even if you’re assigned a project end date. Sometimes senior managers have trouble hearing what you’ve said in your estimate. I use one of these three alternatives to creating estimates for the entire project:
n Provide a date range for the estimate: “We’ll be able to release between May 1 and June 15.” Some senior managers can’t hear the second half of that statement; they only hear May 1. If you work for a manager like that, try either of these other two suggestions.
n Use the word ‘about’ to describe the precision of the estimate: “Five people for about nine months or 10 people for about six months.” You haven’t described an end date, but you have explained the resources you’ll require.
n Provide a confidence level to describe the range of dates: “I have 90 per cent confidence in June 1, and 100 per cent confidence in August 1.” In my experience, even the managers who can’t hear the “between” estimate can hear my confidence levels.
The problem with estimates is that they are guesses. They’re the best guesses we can make, but they’re still guesses. The better everyone understands the project, the better your project management will be, and the more likely you are to meet your SWAG or you’ll know how far off your SWAG was and why. And that knowledge can help you on your next project.