Schedules get a bad rap and it's easy to see why. Here's what typically happens.
Marketing gets the go-ahead to start developing a new product and you (as the project manager) have been asked to put a schedule together to get through the formality of the phase review.
The project manager gets key members of the team together and spend some hours putting the schedule together.
The schedule gets refined over the next few days or even weeks and during the phase review, management asks you to "commit" to the schedule. Ironically, you are asked to "commit" at the point in time you know least about the project. Nevertheless, you do it knowing it means nothing anyway.
Relief as you get through the phase review. Now you can forget about all this formal stuff and just get on with the work because there's no time to loose.
In the next quarterly project review you have to present the schedule, so you update the one you did for the last quarterly project review to reflect the current view. You have a quiet laugh to yourself because the schedule you're updating doesn't remotely reflect what the team did. No surprises the dates have slipped, but it wasn't your fault because the requirements kept changing. It was marketing's fault.
This process continues until the end of the project which ends up being 1 year late.
During the "learning's" meeting, it's concluded that the team needs better tools to help manage the project.
Here's the problem: it's not better tools the team needs, it's a better approach to structuring and managing the work, yet many teams fall into this trap thinking that tools will solve their problem when in fact their problem is a management problem, not a tool problem.
Let's say I give you the next generation word processor. Would it make you write a better novel? Of course not. A good novel has a good story, a good plot with strong characters and a gripping finish. Is a word processor needed - yes, but it's not sufficient to become a best selling novelist.\
Schedules are no different - believe it or not. A good - what we call “fast” - schedule is structured around customer deliverables with a clean hierarchy, has deliverables and activity owners defined, is detailed in the near term for accurate tracking and predictability and is refreshed frequently, often daily.
Teams who adopt these "fast" schedules and are rigorous in using the schedule to drive the work and manage the project, generally finish on-time or early. Now that's an art!