Saturday, September 24th, 2016
Software estimates are usually in terms of Ideal Engineering Days.
Ideal Engineering Days are days where there are no interruptions, no software or hardware glitches, and the implementation moves smoothly.
An Ideal Engineering Day is the amount of development that can be achieved in a single day by the average developer without any interruptions, where there are no dependencies (we can just get on with what we need to do) and no unforeseen interruptions.
In an Ideal Engineering Day, we code for eight hours with no interruptions. No such beast exists of course. An ideal engineering day does not map 1-1 to calendar day and should not do so in the schedule.
Therefore, Ideal Engineering Days are not the same as Calendar Days.
Sometimes there is some confusion about Ideal Engineering Days vs. Calendar Days. In order to avoid this, Story Points is the term commonly used to refer to Ideal Engineering Days.
Summing-up: Ideal Engineering Days (story points) are different from Calendar Days. Estimating a project in 100 Ideal Engineering Days is not the same as estimating it in 100 Calendar Days.