Open Source software is licensed through an open source agreement (such as GPL) that allows organisations to develop and tailor the software to suit local needs, for example, Totara LMS is licensed through GPL. The licence obliges organisations to make any changed source code available to the community to ensure the product remains open and beneficial for all. As a result this reduces the total cost of ownership in a sharing model.
The increasing adoption of open source solutions has resulted in a growing network of user and developer communities who continually review, troubleshoot and improve software code. The open source partner has a responsibility to support each hospital within their Service Level Agreement (SLA).
Support is available either from the communities involved in the development and usage of the software or from the original developer organisation, for example, these could be other hospitals. The SLA agreement will also give you, as a hospital, a support agreement where you can call a partner who can fix bugs for you and walk you through new functionality.
No, given the open source element, you have the flexibility to move from one vendor to another. This gives you control if you are unhappy with the service provided.