How would you motivate your staff to complete the project successfully within the stipulated time and budget?

1. Forecast resources available. 

2. if enough staffs, Provide staffs with task to complete (within their strength) and let them set their goal. (guide if they mislead).

3. let them set due date for submission. (if less time required, tell them for earliest possible for submission).

4. update daily before COB daily and remind them on daily morning meeting by asking whet they try to achieve today (if due date is very critical). 

Summary: By letting them to set their goals, this will help them as self motivation in acieving what they promise for. And by keeping them busy, it will likely make them feel occupied and determine to complete job on time when they feel like wanting to have some free time at work.