Military Communications and Information Technology: A Trusted ...

Chapter 1: Concepts and Solutions for Communications and Information Systems
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The purpose of NSOV-4 Service Orchestration is to describe how services are
used to support an operational processes. The services are used in conjunction to
fulfill an objective that cannot be achieved by any of the services alone. Depending
on how the services interaction is controlled we can distinguish an orchestration
and a choreography. For documentation of such services, activity diagram and
profiles: BPEL and MARTE are used.
In a NSOV-2 Service Definitions subview services are defined in order to
understand an operational domain in terms of services supporting the operational
activities. A definition of service concentrates on the service identification, outcome,
properties (such QoS), interfaces and policies. To document the service class
diagram a SoaML profile is used.
NSOV-5 Service Behavior subview contains detailed description of behavior
and functionality of an individual service. For this purpose sequence diagrams
with the MARTE profile are used.
The purpose of the NSV-1 System Interface Description is to depict which
and how systems collaborate in an operational domain. Term ‘system’ has a broad
meaning and can denote a federation of systems (FoS), system of systems (SoS),
subsystem or a software component. Furthermore, a ‘system’ can denote network
components and other hardware. The subview can document distribution
of software systems to the hardware nodes including connections between them.
To document the resources and software distribution deployment diagrams and
MARTE profile are used.
The NSV-4 System Functionality Description subview describes systems
in more details in terms of their structure and behavior. It’s used to identify and
describe software components which are responsible for realization of functions
defined by the services. To document internal structure of systems, components
diagram, sequence diagram and MARTE profile are used.
The NSV-12 Service Provision subview depicts which systems contribute to
the provision of particular services. It provides traceability between the services,
components and legacy systems layers. Class diagram is used to document this
mapping.
D. Performance model
A performance model is an abstract representation of a system. It describes the system’s
properties associated with a performance domain. It can be used to performance
evaluation of a different architecture designs. The results of the analysis can be used
to support improvement of the system design. This approach allows to detect the architecture
design errors and lower a cost of the errors correction on late development
stages or the system configuration. Many different and widely known performance
models exist, for example: queuing networks (QN), stochastic Petri nets or stochastic
process algebra. In this work the Layered Queuing Network model is used [2].