I think the first consideration is ease of use for those who need to operate the system. The onscreen information should be user-friendly with clear instructions. You also need something that is easy to correct. If you select the wrong action, is it easy to stop and amend it? If several people will be using it, are there safeguards to lock key decisions that you do want to have changed?

Think very carefully about what will serve your needs. You may want a global package that handles multiple administrative procedures or you may want a stand alone time-tabler. Discuss the criteria with the people in your school who will actually have to use it. It will be pointless buying a product that they find unhelpful or too complicated.

Check with your potential supplier as to which schools actually use their product and get some feedback from users. Ask users about any problems they have and about the quality of the aftercare service.

Ensure that your supplier will not insist on your buying more features than you actually need. A reputable supplier should be able to come to your school, listen to your needs, make an assessment and then suggest a product that is adapted to your situation. A small school with 100 students is unlikely to need the same package as major college catering to thousands. Also, find out what provisions they make for updating the package with new features.

Try out free software from the Internet first so that you get an idea of the features you will find useful. Buying the right software is likely to be a major investment, so it's worth choosing it with care.