CONFIDENTIALITY IT systems can be judged on their non-functional aspects, such as performance and resource usage. A common trio of non-functional aspects is Confidentiality, Integrity and Availability. Confidentiality ties users together in a private communication. Usually, this is put differently: confidentiality expresses the norm that information is only meant for an exclusive group of people. But, as explained above, as Perspectives is goal-directed from the ground up, we can see that these are the very people that communicate because they co-operate. In the world of Perspectives, ‘information’ comes secondary; Actions of Roles are primary.
As a Perspectives Model expresses concisely and precisely what the Actions of Roles are, we actually can compute what users should be supplied with what information. This is how the distributed runtime supplied by Perspect IT – the PDR – operates. Each peer node (PDR) in the network computes, when its user performs an Information Action other than Consulting, what changes should be sent to what users. This creates a distributed infrastructure with a simple invariant: each user has all the information he needs for his Actions, at his disposal. Perspectives creates a distributed, not-centrally-governed infrastructure for situational awareness for knowledge workers.