Triple Constraint (Scope, Time, Cost) plus Quality
What work will be done as part of the project ? what unique product, service, or result does the customer or sponsor expect from the project.
How long should it take to complete the project ? what is the project’s schedule ?
What should it cost to complete the project ? you must understand project’s budget.
Quality considerations, including customer satisfaction, must be inherent in setting the scope, time, and costt goals of a project. How can you avoid the problems that occur when you meet scope, time, and cost goals, but lose sight of quality or customer satisfaction? The answer is good project management, which includes more than meeting the triple constraint.
The most important things are, you must complete them all with an excelent leadership. Good leadership means you trust 100% your teams profesionalism. You dont need to controll them strictly, let the teams show all of their creativity. and make sure your teams always happy and enjoy when they works with you.
Project Management, Kathy Schwalbe. 4th Edition.