Useful business software? None! My experience is that often software creates problems and cannot replace a person.
The problem is that managers think that computers are a solution to all their problems, but they are just a tool. They can be a helpful tool, but they are not magic
For example, I have seen companies try to replace secretaries by giving all office workers a computer. The result is that paperwork takes longer, stresses the worker (who has to do the work of a secretary instead of their own work, whilst being paid more than the secretary was) and letters and reports are full of spelling, grammar and formatting errors that the software failed to identify (or in some cases, "corrected" incorrectly - Microsoft Office often does this!)
The situation is particulary dangerous in science: a young and inexperienced employee will often rely on the computer without carrying out simple hand calculations. An old mentor of mine used to get young employees to solve a problem: they would invariably model it on a high-powered computer with some software that costs around £10000 for a license, taking several days. He would then compare it to his own calculation, which took under an hour on a single sheet of paper!

The computer model sometimes gave a silly answer, but sometimes it gave an answer that looked believable but was missing an important parameter.
The computer is useful for performing lots of boring calculations that could take a person years... But they should always checked, otherwise a huge amount of time and money can be wasted.