Project management software will not manage a project. It can help you identify issues, track costs, and do many valuable things, but it will not replace management.
Project management can be greatly simplified into the following statement:
With these resources, do this work, in this amount of time.
The resources can be people, money, time, or tangigble items like lumber and concrete.
Assuming there are adequate resources, the work should be completed within the timeframe.
Although cost isn’t specifically mentioned, again, it is assumed that if the project is done on time, the cost was within the budget.
The entire team must manage itself as individuals with the attitude that for a given task, they can use a finite amount of resources (time, materials, money). If each team member stays within budget, the project succeeds.
The budget usually represents estimates given. These estimates include assumptions about the scope of work. It is the responsibility of the estimator to clearly state important assumptions, and the responsibility of management to take them into consideration. Once the estimate is given, it is binding only within that context.