In general, Koha is going to be most appropriate for small libraries.  Koha has been especially popular with small public libraries and school libraries.

The next step is to create a list of the necessary features of your current ILS. This is a great opportunity to include the whole library staff. Have each department (Circulation, Acquisitions, Cataloguing) create the list for their department. Compare this to the current version of Koha. If you can show your staff that Koha has the same features as your current ILS, it should reassure them. If you can show them that Koha has more features than your current ILS, they should became more supportive. If there are things on your list that are not currently available in Koha then you have three options: 1) wait until it comes available, 2) decide that you can live without it and migrate anyway, or 3) develop it working with a vendor, in partnership with another library or by yourselves.

At some point early in the process, it will be necessary to create a migration team. These are the people who will actually carry out the migration. There are several ways to choose this team. A couple of points to keep in mind, the more excited and open to OSS ILS the members are the more likely they are to do a good job. While having technical skills makes the process easier (so if you have people with those skills definitely include them), it is more important to have people who will seek out answers and are willing to learn the needed skills. If you are going to work with a vendor, designate a liaison between the migration team and the vendor. That way there is a clear line of communication and the vendor doesn't have multiple people asking them the same questions. 

Best Practices for Evaluation
  • Make a list of requirements and don't migrate until they are all there.
  • Know your staff's abilities before committing.
  • Talk to other libraries.
  • Include as many people as you can in the decision to move to open source.