User interface

The user interface layer is a consumer of services, just like your BPM component, but it can also be a service in itself.

Note

Services are often regarded as automated components without a graphical user interface such as web services. However, services can have any interface, also a user interface. An example is a service PrintService that provides a portlet interface for creating print tasks. Another example is any app from any app store.

In silos, users have to switch between using different user interfaces during the execution of a single task. For example, an employee in your HR department might need to switch between her email client, HRM application, financial application, and network file system containing documents to finalize salary changes. The main reason is that these applications were designed as separate (or “stovepiped ”) systems without looking at other systems or looking at the end user’s needs. This situation is shown in the following figure:

In an SOA, landscape...