ScrumWorks Pro 3.0 (MySQL) shipped with a maximum connection pool size of 20. ScrumWorks Pro 3.1+ (MySQL) ships with a maximum connection pool size of 50. This is often sufficient for moderate use, but organizations experiencing connection pool issues will need to increase this value. Users will see an error "No ManagedConnections available" when the connection pool is insufficient.
Contact your MySQL administrator to find out what you can safely change this parameter to. You can increase the connection pool size:
INSTALL_DIR/server/scrumworks/deploy/scrumworks-mysql-ds.xml