how to measure time

[John Anderson <joa -at- CRAYCOM -dot- DK>]

Troops,

Perhaps someone can be of assistance.....

In general, how do you estimate how long a technical writing
project (fx. writing a manual) is going to take?

Are there any industry-standard ways of measuring/estimating
this? Or any half-decent rules of thumb?

Cheers for any help,

..... John