If three people are all counting on using the video projector at the same time, two people are going to be disappointed because the projector will not be available. This can cause major problems when all three people feel they have a right to use the projector at a certain time and think are going to have it. Even though a projector may be rented if several people need a projector at once, it can be difficult to rent the projector at the last minute.
Imagine how you would feel if you walked into the storage room to grab the projector to take with you to an important meeting, only to discover it is not there. You have your presentation ready and everything is in order but you no longer have an important resource. Some people would be looking to have a very unpleasant conversation with a coworker.
If you use resource scheduling software, you can keep track of many of your company's resources to know when the resources are available and when they are not available. The confusion of thinking a particular item is available, when it is not, can be removed. Arrangements can be made so individuals have everything they need without conflict.
A little over a year ago, I had the responsibility of setting up a room for us to use in a hotel for a series of meetings. The hotel had a specific person in charge of overseeing all of the banquet rooms and facilities available for customers to rent. This person needed to know which rooms were in use, when they were in use and which groups were using the rooms.