TT_Vol3 Issue2 - Raytheon

product; an integrated dictionary
manages the inter-relationships
between them.
Application and use of DoDAF and REAP are
growing within Raytheon through individual
efforts and the efforts of the Architecture
Technical Interest Group (TIG) sponsored by
the Systems Engineering Technology
Network (SETN). The DD(X) program, along
with other programs in Garland, use Popkin
SA for CAF/DoDAF architecture development,
linking their architectural elements to
requirements in DOORS. DD(X) has extended
the Popkin SA meta-model to accommodate
specific interface definition and specification
tree structures.
Raytheon has also used the Ptech Enterprise
tool to develop Zachman and DoDAF views.
Ptech’s concordant knowledge base was
used to create the AV-2 and the OV-3 for a
portion of the Military Information
Architecture Accelerator (MIAA). Raytheon
used the Ptech software to publish a CD,
allowing the customer to examine the architecture
through a web browser and also
exported the OV-5 activity model as code
for a Colored Petri Net simulation.
Other programs use the Extend modeling
tool to run system performance Analysis,
helping them better understand and derive
complex system requirements. Extend has
also helped Missile Systems model Netted
Weapons Systems architectures using simulation
to measure the "power" of alternate
IR&D and NetCentric approaches. Network
Centric Systems has built elaborate Extend
models used to test out SoS architectures,
building executable Concept of Operations.
As the DoDAF products mature, information
can be flowed down to the system analysis
and design models for additional analysis
and refinement at the system level. Table 1
shows how the DoDAF products can provide
useful information to the Performance
Analysis, System Design & Specification,
and Specialty Engineering capabilities. The
following paragraphs define each of these
advanced capabilities in more detail.
Mission Analysis Examples of Information to be Exchanged: Example Exchange
Interface to: Format/Tool: Standard
1. Performance Simplified Mission Scenarios Extend
Analysis Force-on-force performance EADTB
2. System Design DoDAF AV/OV/SV/TV (System context, operational Popkin SA, Ptech, UML 2, XMI,
and interface constraints), Tau, Rose SysML, AP233
Mission Requirements DOORS DXL
Use Cases (mission and system requirements) Use Case templates
3. Specialty System of System Availability and Cost Tradeoffs CALCE PWA SPAR
Engineering CoSysMo, CoCoMo
Ultra-reliability eXpress DiagML
Reliability predictions FMECA Asent
Table 2. Mission Analysis Interfaces and Tools
System Design and
Specification
Raytheon has considerable experience
applying sophisticated system modeling
tools like Foresight, RDD-100, CORE and
StateMate to solve complex system design
problems. These tools are used to develop
static and dynamic holistic models of the
system, as represented in Figure 3. By
carefully controlling the level of abstraction
of the system’s internal components
and interfaces, over-specification and unnecessary
design detail
can be avoided.
Raytheon continues
to gain experience in
using automation to
extract specifications
from well-structured
system models. This
powerful capability
has provided
unprecedented
insight into the
system design as it
matures. By checking
requirements traceability,
functional allocation, interface completeness,
and dynamic execution of the
system model, Raytheon has shown that
the completeness and consistency of the
resulting specification can be assured. In
addition, a well structured system model
provides a flexible framework for relating
performance budgets to system components,
identifying detailed analysis needs
and relating analysis results back to the
overall system context. The analytical techniques
that are used have included closed
form expressions, discrete event models and
network analysis.
The Unified Modeling Language (UML), a
popular software modeling language, is
Figure 3. The Holistic System Model Comprises both
Form and Function for each system alternative
Figure 4. The System Model is a Framework for linking
Requirements and Analysis to System Design
now showing promise as a systems modeling
language. Raytheon is an active participant
in SysML Partners, currently defining
conventions for use of UML 2.0 in Systems
Engineering (http://www.sysml.org). SysML
emphasizes a flexible component-based
model-driven approach to system specification,
promising the encapsulation and reuse
of Object Oriented techniques as well as the
strong interface management necessary for
successful MSI. SysML supports allocation of
function to form and facilitates system tradeoff
and technology upgrade Analysis.
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