Once you can tell reliably tell me you're going to deliver 10% of the remaining total work in the next two weeks, I know for a fact you have 18 more weeks left in the project.
Really? I would automatically estimate 38 more weeks.
The difference being that once someone is confident of their figures for time periods that long, they are generally wrong by a factor of 2.
In essence this is a disagreement about what "reliably" means. But in general time estimates tend to be "the smallest number that nobody can prove is wrong" rather than "how long this is likely to take". And you can tell that because there is a nice little plan, and a breakdown of how long each step could take, with no big fudge factor for "Things we don't know about yet, like the requirement that we'll get told about in 2 weeks."
Really? I would automatically estimate 38 more weeks.
The difference being that once someone is confident of their figures for time periods that long, they are generally wrong by a factor of 2.
In essence this is a disagreement about what "reliably" means. But in general time estimates tend to be "the smallest number that nobody can prove is wrong" rather than "how long this is likely to take". And you can tell that because there is a nice little plan, and a breakdown of how long each step could take, with no big fudge factor for "Things we don't know about yet, like the requirement that we'll get told about in 2 weeks."
Cynical? No, realist( * ). ;-)
* Cynics always claim to be realists.