Plan to Be Behind Schedule

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  1

  pt_boss@...

  08/18/08 | Report as spam

  RE: Plan to Be Behind Schedule

  The best approach I've used to manage the under-estimation problem is a risk-based timeline. It essentially comes down to:
  
  1. Take a shot at your estimate.
  2. List all the things you know could go wrong, how likely it is to go wrong, and how badly things would go wrong if the situation occurred.
  3. Rate the risk level:
  - If it's low risk, give it a 10% buffer
  - If it's medium risk, give it a 20% buffer
  - If there's a high risk, give it a 30% buffer
  4. Buffer for pain:
  - If you've got complete control over everybody and everything involved in the work add 5%
  - If not, add 10%
  - If you know someone responsible for some kind of decision has a hard time making and/or sticking to decisions, add 20%
  
  This should wind up with a buffer between 15-50%
  
  Whatever the final top result, what you communicate provides your last safety net. I generally communicate between 5% under and 10% over that final number. You can always come under if it turns out easier than expected.

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  2

  eclectos

  08/18/08 | Report as spam

  RE: Plan to Be Behind Schedule

  My 2 Rules for good Estimating:
  
  Rule 1:
  Take your honest, well thought out, best guess. Not in your wildest dreams, my friend.
  Now double it (2x). If NOTHING goes wrong,you just might be right.
  Now double it again (4x). With just a little luck, this is pretty close to accurate.
  Now double it again (8x). If EVERYTHING goes wrong (see Rule 2), this is usually pretty accurate.
  
  Rule 2:
  Whatever CAN go wrong, WILL go wrong.
  
  Personally, I use the 4x number and sacrifice a goat at the start of each project.