Answer to Question 1
There are different ways that computer programs can be set up. To that end, the
information provided by them can be derived by different means and the information may
not always be consistent between programs. In order for this to not be an obstacle, it is
important that the user of the information has a clear understanding of the means by
which the information was obtained. This understanding may well be lacking if the user
cannot independently generate the same information. This is not to say that the user must
verify the scheduling output, but the user must be able to critically assess the information.
This will not be a task readily performed if the user does not have a very good
understanding of the scheduling process, especially the manual computations.
Answer to Question 2
As-built schedules are after-the-fact portrayals of how a project was actually
constructed in terms of sequencing of activities and the dates over which they were
performed. While the sequencing may change somewhat from the as-planned or original
schedule, the information of particular value will relate to when activities were actually
begun and how long they took to complete. This information has various uses. Just as
cost information is valuable for making estimates on future projects, schedule
information is valuable to both schedulers and estimators when new projects are being
considered. Thus, future schedules may be more accurate when based on actual schedule
data from prior projects. As-built schedules are also very useful when disputes arise as
they can help to show how various types of occurrences (changes, delays, suspensions,
changed conditions, etc.) adversely impacted progress on a project.