The NSV-1 System Exchange Compliance Chapter
This chapter indicates the level of compliance between the need to exchange information from one system to another and the information actually exchanged through the implemented missions.
Tasks supported by the systems actually exchange information within the context of designed missions. This information is compared with the need defined in the needlines/interactions. Missing or unexpected information is detected.
This chapter relies on the systems defined in the NSV-1 subview as well as the system processes that describe how missions are performed. These processes are described in detail in NSV-4, however, a brief description is necessary to aid in understanding the content of this chapter.
A system structure does not indicate how missions are performed. It only describes the systems involved in the mission and how they are structured. Through interactions, you can guess the potential information exchanges that occur between systems. To add a dynamic perspective to systems, a process must be described (see the NSV-4 subview). This process is composed of tasks that exchange information. Information is actually exchanged in the process while the system structure only describes the ability to perform such exchanges.
Tasks are performed under the control of resource architectures, applications and artifacts.
The System exchange compliance chapter identifies three states for the information exchange:
• Information Exchange Correctly Designed: an information item is defined at both the system and the process levels.
• Missing Information: an information item can potentially be exchanged between two systems, however, there is no process available to perform this exchange. The question is therefore, whether the interface described between the two systems is still useful.
• Unexpected Information: an information item is exchanged in a process between two activities (tasks), however, there is no interaction between the systems carrying out the activities (task). The question is therefore, should the information be exchanged in this manner in the process and must the interaction be reviewed to depict the ability to make such an exchange.