A family of Microsoft relational database management systems designed for ease of use.
Using Visual Basic for applications, you can write any code/note you wish. The challenge becomes defining what problems you are looking for, and then how to notify the user. I have written an Add-In for MS Project 2007 and later that makes over 30 tests on the schedule and then displays in the flag or text field of your choice. It also will put it into Excel very nicely. Not freeware, just letting you know what is possible with code ...
What you can do quite quickly and easily is insert the column "Status" or "Status Indicator" and it will let you know if a task is behind schedule, etc. That comes as out of the box behavior.
Now to get a bit more robust. Suppose you are looking for detail tasks that have a finish date that has slipped from the baseline. You can set a formula in any of the 20 custom flag fields iif([Finish Variance]>0, "yes", "no") which will set the Flag to "yes" of there is a positive finish variance. You can change the 0 to 5 or whatever is a desired threshold. Then, rename the Flag field to be something like "Late Finishes" and that becomes your note. Since there are multiple custom text, flag, and number columns, you have a lot of places to store your results.
To create the formula, insert the field of your choice into a view. Right click on it (say Flag1) and select "Customize Fields" In the dialog box, you can set a formula.
Finally, after customizing the Flag field, you can use a display indicator. The ability to display a flag, circle, dot, triangle, square, etc. of various colors is a good way to bring attention to a specific set of tasks (you can even filter to it, ie: Flag1="yes").
To get much more complicated than this will require the use of code.
If this post was helpful, please click on something :) I am also at http://www.msprojectblog.com Jim