How is Software a constraint in business?Watch
It might be contributing to time limitations if the software is running slowly, or if it takes certain time to do things.
You've also got the problems of employees not knowing how to use the software. Can you go to Excel and produce a formula that colours all cells with a number "6" in pink? Probably not, but Excel can do it. This is a knowledge constraint. Similarly, the software might not be able to do something that the business needs - you can't really write an essay in Excel, so the business would need 2 pieces of software.