2 = Someone else in the organization has done this before
3 = Someone outside the organization has done this before.
4 = Nobody has done this before
1 and 2 can be quickly estimated by referring to past work.
3 and 4 must be broken down into small tasks that are estimated.
And when breaking things down into tasks to estimate, keep in mind coding is only around 1/4 of the work to produce software. There’s tests, documentation, revisions, planning, and communication.
For 4 (and sometimes 3), you need a mini-project for exploration. "After 2 months of work, then I'll be able to give you an estimate." Management never wants to hear that, but sometimes it's the truth.
1 = I’ve done this before
2 = Someone else in the organization has done this before
3 = Someone outside the organization has done this before.
4 = Nobody has done this before
1 and 2 can be quickly estimated by referring to past work.
3 and 4 must be broken down into small tasks that are estimated.
And when breaking things down into tasks to estimate, keep in mind coding is only around 1/4 of the work to produce software. There’s tests, documentation, revisions, planning, and communication.