This is one of the best features of project management. There is a beginning, an end, and a schedule for completion. By definition, projects have a finite life. As we look at project management tools and techniques, you will see that good time estimates and scheduling are critical for project success. There is a budget.
Resources are limited.
Few, if any, of us ever get a blank check for our projects. There are always limits to the money available, people who can work on the project and other resources. The project manager's job is to first determine what resources are available and then to effectively integrate and allocate those limited resources for project success. Other people are involved in your project on an ad hoc basis. Projects are completed by teams.