43. For NCF systems and NII it is desirable that the NISP should provide an ability to share common applications and services.

44. Achieving the highest level of interoperability (i.e. guaranteeing that the interpretation and rendering of information is identical within a Community of Interest) frequently depends upon the use of common applications or services (for the same CIS security classification level). Even the best import/export filters can lose or corrupt important elements of information in the process of mapping between formats and encoding standards. In the past application portability was cited as a way of achieving this and deriving benefits from software re-use, but application portability has never been truly realized. However, the ability to have cross-platform availability of applications is achievable by executing applications on a remote server and rendering the display remotely on a user terminal. Hence, in a heterogeneous server environment, users with dissimilar desktops (such as Windows and UNIX) can still access essential applications. The widespread adoption of a Service Oriented Architecture which focuses on the interface, independent of the service implementation, further supports interoperability.

45. Application and service availability also delivers further benefits in the form of reduced training costs (see Section 1.5.3). It also allows the range of different applications and services to be limited, thus limiting diversity and delivering benefits through the reduction of through-life costs (see Section 1.5.2).

46. For NCF systems and the NII it is desirable that the NISP should support an architecture which can embrace technological change and manage obsolescence without the need for radical redesign.

47. The ever-increasing pace of technological development has meant that obsolescence becomes an issue even as systems or services are delivered for the first time. Reducing life cycle costs requires the management of technology obsolescence, which effectively requires key decisions to be made that avoid lock-in or a high dependency on specific products. Systems must be able to evolve in such a way that technology can be refreshed without the need for fundamental redesign.

48. Technology refresh will inevitably increase diversity. An architecture that permits, but manages, diversity will provide a much better environment for the management of obsolescence.

49. For NCF systems and the NII it is desirable that the NISP should reduce the need for training (and retraining) of personnel in the operation of workstations and applications.

50. Personnel within NATO are required to move within the organisation to execute their role or when changing roles. To make such movements and transfers as efficient and easy as possible it is essential that users are presented with an interface to the services they need that operates and perform in a way that is common across NCF systems and the NII. Adopting a common look and feel through the use of common Human-Computer Interaction (HCI) and style guides will facilitate people portability.

51. Closely linked with people flexibility, there is a need to minimize the amount of training required when personnel transfer between systems. This can best be achieved by adopting a common look and feel to the user interface and adopting a common style guide for application providers.