Break-fix or break/fix is a model for delivering IT support that focuses on providing a service when repairs and updates are required. If something is broken, the service is available to fix it. If you have a short-term project to upgrade or improve something, you can enlist the services you need as and when you need them, and you won't have to pay for anything that isn't required. You pay per service, rather than paying an ongoing amount for ongoing services.
For more info: Break Fix Engineer