This is the oldest but trickiest project management goal in the book. It's the most difficult because during the project and because the original schedule was probably optimistic in the first place.
To accomplish this goal, you need to manage your scope very carefully. Implement a change control process so that any changes to the scope are properly managed. Always keep your plan up to date, recording actual vs. planned progress. Identify any deviations from plan and fix them quickly.
To make sure that your project costs don't spiral, you need to set a project budget at the start to compare against. Include in this budget all of the project costs that will accrue, whether they have to do with people, equipment, suppliers or materials. Then work out how much each task in your plan is going to cost to complete, and track any deviations from this plan. (See Project Management: .)