We built a Complete, Integrated Hospital Information Management system
with its own Data Access layer, but last year we released a new version
of the software with the Data Access Layer using Hibernate. 

Subsequent to his we Installed the V2 of the product in multiple
hospitals with more than 500 beds, about 800 patient encounters per day,
1000 lab tests each day and 500 to 600 patient drug issues each day.
This product has completed a year in production deployment and we are
happy to announce this success here. Using hibernate had some obvious
advantages and it has helped us well in the following areas:

1. Customizability : No two hospitals are the same and each have their
own modifications to the schemas and the application that was a problem
before using hibernate. But now with hibernate mapping files defining
the schema for the database and also the object model, we are able to
cascade changes from the Hibernate XMLs into the UI layer, BL layer and
the Database. THis has ensured that we can make modifications to the
application before deployment in a much shorter time span. 

2. Database Agnostic : We are able to suggest to customers that choice
of the DB is theirs based on their requirements which is very
comfortable for our customers.

3. Scalability:  With the kind of metrics I mentioned above, each of our
customers is a big hospital with a lot of data to be processed. In just
the last one year our application has been used to process more than
200,000 patient records without problems and is going pretty well. 

Thanks for a wonderful product. 

Sarath.
http://www.quadone.com