Frank,
In my opinion, everyone should be compensated for overtime. Besides the obivious company profit motive (greed?), the only reason I can see the need for salaries with no overtime is company budgeting.
The National Labor Relations Board determines which postions are exempt and do not get overtime and which positions are non-exempt and are paid overtime. Most lower IT positions like data entry are non-exempt and most higher positions like IT Director are exempt. (See the National Labor Relations Board for more information on exempt and non-exempt positions.)
I have worked in IT for over 20 years. The only time I was paid overtime was when the company fired our 3rd shift computer operator. The guy went to the National Labor Relations board and the Federal Government forced the company to pay us ALL overtime for ALL hours over 40, since we had STARTED with the company. We really liked that guy after that, even if he was not there!
So if you are in data entry or computer operations and you are not getting overtime, keep your signed time sheets and after you leave the company, talk to the National Relations Board. I do not recommend doing this while you are employed. I think you will create a very tense situation and will probably have to leave the company. But after you leave.............
For my other 3 jobs I have been paid a salary. When I asked employees about overtime, they said it was already built into the salary. I looked at market salaries for my type of position and I was paid over market. So I did not say anything to management. I felt overtime was built into my salary. But if you are not being paid with over an over market salary and you are not paid overtime or compensated for it, I would look for another job. The chances of changing salaries levels at your company are very low, unless you are the President and CEO of the company.
However, if you are in a exempt position, working overtime and you are paid or compensated for it, I would ask management politely why you are not being compensated. If all they can say is, "It's part of your job," I would look for another job.
I hope this gives you some ideas.
Reed