My motto is: If your project has finished exactly according the original plan, it is most likely that you had made the wrong plan.
Planning, better think of scheduling, is both a profession and an art. On the other hand it is no rocket science, although it may have to do with rockets. Just using your brains, gut feelings and an occasionally calculated guess [called gamble by others], together with the most important people motivator skills, are primary factors for success.
Just updating the project plan, moving to the Status Date of unfinished (parts of) tasks that should have been completed change your plan. Adding resources or sometimes even taking resources off some tasks in order that the remaining can work more efficient and quickly is again a change. Allow tasks to run in parallel or have overlaps that were initially scheduled sequentially, even skip certain (gold plated) tasks. That all together makes the job of a project manger interesting and at the same time threatening. Because if you have bosses that believe a project plan to be cast in concrete, your life will become a misery. Better change jobs in such an environment. MS Project is a TOOL in order to see work at hand, Deadlines that will be violated if no measures are taken. If you work with resources it can help to stop overloading, allowing levelling, monitoring and showing status, generating reports, allowing many views on your giant database with project data and much more. The problem is that many people use it only to draw Gantt bars, just with constraints [if possible cast in concrete with some MUST] rather than really using it as a scheduling tool which requires constant updating and amendments.
The Baseline is required to see momentary changes, thus to spot if there are slipping tasks or even tasks that finished earlier than planned. [These miracles may happen in a good plan or happen regularly in a plan that was set-up with much too much ÿou-never-know-how-fast-it-goes-just-let's-take-in-each-task-some-extra-time-to-satisfy-that-ignorant-boss]
So, contemplate these thoughts, stop nagging and start updating your plan as often as required. Success with your efforts!
By the way. There is also a new trend to use Monte Carlo simulations in order to have a better insight in Early Finish and Late Finish of your project, including taking into account of probabilities that a major machine might break down and that type of worries for a project manager and the bookkeepers. In real life those bookkeeper are usually the people most wasting money by abiding to their budget headings, always seeking the cheapest supplier, having never heard of quality, maintenance costs [that are nowadays often part of a lump sum contract] and lean building/constructing that may speed-up the project at higher article costs but lowering considerably labour costs and interests to be paid during the project.
MS Project has, at least in the older versions, a simple tool Pert Analysis to get an idea about Early, Realistic and Pessimistic Task Duration.
Why an easy solution if you can make it complicated?
Greetings from the Netherlands
