Quality assurance comprises a growing share of software development costs. To improve reliability, projects should focus as much effort on upfront planning an estimation as they do on remedial testing and defect removal. Industry data show that simple changes like using smaller teams, capturing average deviations between estimates and actuals and using this information as an explicit input to future estimates, and tuning estimates to an organization's historical performance result in lower defect creation rates. Access to accurate historical data helps projects counter unrealistic expectations and negotiate plans that support quality instead of undermining it.