“Change Control is the Project Manager’s friend. It’s more than a friend, it’s your best friend. Without Change Control, your project is out of control.”
Here beginneth the simple lesson:
At the start of your project, before you do anything else, create a Change Control Note. Make sure it contains ‘effort required’ and ‘cost’ sections.
As part of your initial planning of the project, hand a blank copy to your opposite number – your customer or PM counterpart. “This is to make sure we can keep everything under control”, you will say.
The first few weeks of the project, find as many opportunities to raise a Change Control Note for changes to the spec, deliverables or anything really. Make these indicate small effort required and most definitely zero cost. Make sure your oppo signs this and make sure they know that you’re a good-guy. See ‘good-guys’.
Then, when the time is right, stiff them with a costed up one. Make sure you estimate this one accurately and have plenty of back up to prove it.
This is a good way to buy yourself some time, by moving out the deadlines, or be able to afford to get your team-size increased.
Later on you can graduate to the school of ‘comfortable’ estimation to allow you a bit of extra cash in the budget for other things, like the things you forget about. See ‘slush-fund’.