> Demanding perfect time-boxing ahead of time is a recipe for disaster.
Dear client, this task will take 2 to 6 hours. If I find out it will take longer than this, I will reach out.
Dear client, I am 1.5 hours into this task. Based on my experience, it look like it will take 7 to 10 hours instead. Should I continue?
For all of this to work well, you need to have experience in estimating well and also understand that whatever number pops into your head, multiply it by 2 and tell the client that. I have never had a client be pissed at me because I finished something for less time/money than they were expecting.
That said, this sort of thing should really be used for highly indeterminate tasks, like fixing bugs.
Dear client, this task will take 2 to 6 hours. If I find out it will take longer than this, I will reach out.
Dear client, I am 1.5 hours into this task. Based on my experience, it look like it will take 7 to 10 hours instead. Should I continue?
For all of this to work well, you need to have experience in estimating well and also understand that whatever number pops into your head, multiply it by 2 and tell the client that. I have never had a client be pissed at me because I finished something for less time/money than they were expecting.
That said, this sort of thing should really be used for highly indeterminate tasks, like fixing bugs.