Deployment solutions based on Java Enterprise System typically fall into two general categories:
The 80:20 and 20:80 categories are broad generalizations. The exact percentage of the type of services offered is not important. However, the percentage indicates the amount of customization a solution contains.
Java Enterprise System is well suited for 80:20 deployments because of the rich set of services provided by Java ES. For example, it is relatively easy to deploy an enterprise-wide communications system or an enterprise-wide portal system using services provided by Java Enterprise System.
For deployments that require custom development, Java Enterprise System supports the creation and integration of custom-developed services and applications.
Most of the service categories listed in System Services can be used to deliver 80:20 deployments. For example, communications and collaboration services provide email, calendar, and instant messaging services to end users, allowing them to aggregate and personalize the content. Similarly, the network identity and enterprise portal categories of services allow you to install and configure enterprise-wide applications without developing or integrating custom services.
Enterprise solutions that require custom development of J2EE platform services can leverage Application Server, Message Queue, or Web Server which are provided with Java Enterprise System web and application services.
Enterprise deployments can vary greatly in the number of custom-developed services they require. Because of the interoperability between Java Enterprise System services, you can create your own suite of services tailored to your particular enterprise needs.