Good Estimates Come From Good Designs

The most important thing about good estimates is that they only come from credible designs and requirements. Good engineering estimates are possible only if you have two things: good information and good engineers.

Here are some additional ways to ensure good estimates:

• Establish baseline confidence intervals for estimates.
• Lead programmers must set the bar for quality estimations by asking good questions and taking wise approaches that the team can emulate.
• Programmers should be trusted.
• Estimates depend on the programmer's understanding of the project goals.
• Estimates should be based on previous performance.
• Specification or design quality should be to whatever point engineering needs to make good estimates.
• There are known techniques for making better estimates. For example, PERT.

Adopted from The Art of Project Management by Scott Berkun.