An instance is created for each client connected to the server.

It can have a create() method that accepts arguments.

It has a state or member fields that can be initialized and changed by the client with each business method invocation.

It can never be passivated or activated by the container.

The bean instance is stored for later reactivation.

The bean instance is evicted from the application server memory.

The bean instance is created and becomes ready.

The bean state is serialized except for its transient member fields.

More than one caller is concurrently connected to use the service.

Persistence is a primary requirement.

Instance is required to be thread-safe.

You want to manage client state in a transactional and secure environment.