If you are going to work on it only a few hours a day, I find that a huge time waster for me is getting back up to speed where I left off.
(Often I'll work a day or two straight on something complicated otherwise I waste half my time trying to remember where I was).

As far as calculating time (and cost), the job detail is pretty vague. Sort of like asking "How much is a car", there's a whole spectrum from the Yugo to the Bentley. I'd be very careful to state everything that you are and are not contractually obligated to perform and guarantee.

When I first started working for myself, I played it fast and loose. I've done a lot of different types of projects and my <nobr>"Guesstimates" ™</nobr> have always been really close... until.. I had a client that expected our 5 figure software to do everything that there aborted 7 figure software couldn't do. Do to the lack of a rigid spec, it was a painful ordeal. Luckily they had a burn rate on the order of a super nova so the problem resolved itself.

I know this doesn't really help come up with an estimate but I hope it gives you a bit to think about.

Whenever I am quoting a job, I mentally map it out into the base components and actions and think can I do this easily? Have I done it before? If the answer to the latter is no, I do a proof of concept real quick to determine the complexity.

When all else fails, come up with a reasonable and realistic guess of cost and time frame and then double it. :)

-Lee

"To be civilized is to deny one's nature."

In reply to Re: How to calculate development time? by shotgunefx
in thread How to calculate development time? by Siddartha

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.