What are the basic needs for planning a successful project?

You have to have a good project management plan and busines objectives, i.e from developing a project charter up to closing the project which include all of the following, budget, schedule, tools & tecniques, resources, enough but reliable and competent manpower (including the Project Manager) that needs top management support

A well achievable strategic goals and objectives. An executive management support. A well qualified project manager who can drive and lead this project efficiently without any kind of conlict of interest.