Tony Elliston
SIGADA Atlanta Nov 2005

• ‘State of the Art’ software modeling tool
• Already deployed & supported on many critical projects (
DO-178B, ECSS-E40, MIL-STD-498)
• UML 2.0 front end & AADL 1.0 plug-in
Sof tware
Requirements
Analy sis
Sof tware
Design
Stood Sof tware
Coding
Sof tware
Unit
Testing
Sof tware
Functional
Testing

• A textual notation
• A graphical notation
DataManager.FileStorage
20 store: file: acquire:
• Ideal fit for critical system and software:
DO-178B ECSS-E40 MIL-STD- 498 ...

• Architecture Analysis & Design Language
– new SAE standard
– manages System and SW components
– supports Real-Time and SW to HW binding
– may carry non functional properties
• Can be used as:
– output for the System Design process
– input for the Software design process
Add such an output to System process to formalise System specification for SW

Using the AADL for critical SW development
• AADL for Real Time System Modeling
• combined HW & SW descriptions
• explicit Real-Time constructs
• use language extensions for specific domains
• AADL specification as a blueprint for
Software architecture
• reduce the gap between System & Software
• while preserving the benefits of current practices
• and enforcing reuse of Components at high level
• AADL as a communication language throughout the development process

software requirements
SW design documentation system specification
(AADL) source code reusable software
SW design verification
Use the System design model as a blueprint for SW architectural design

Recommendations for software methods and tools
• Model based for better flexibility
– as opposed to code based
– more semantics: real-time abstractions, multilanguage, ...
– formal transformations (code generation, ...)
• Component based to manage complexity
– interfaces to control interactions
– composition hierarchy to control the architecture
– avoids "spaghetti-ware"
• Strong methodological support
– naming rules, visibility rules, ...
– to encourage effort at the early stages of the life cycle
Need for hierarchical component based method and tool

• AADL compliant commercial tool
• well defined step-by-step modeling process:
– capture of functional and non-functional requirements
– graphical design of the architecture (UML 2.0-HOOD-AADL)
– multi-language detailed design and coding (Ada, C, C++, ...)
– static design verifications
– code and documentation generators
– reverse engineering (i.e. Ada -> AADL)
• ready for industrial projects:
– multi-users, configuration management, requirements traceability
– Unix-Windows interoperability
– Complies with process standards:
DO-178B, ECSS-E40, MIL-STD-498
Already in use in many large scale critical projects (including A380)

SW Requirements
------------------
Ada legacy code
C legacy code model transformation plugins
GUI
DataBase interchange
AADL
XML/SIF
Conf. Management
Req. Traceability
Verification reports
-------------------
Source files:
-Ada 95
-Ada Ravenscar
- C/C++
-------------------
Documentation:
- PostScript
- PDF
- Word
- FrameMaker
- HTML kernel

www.tni-world.com
AADL

Stood
Components repository
Stood
Generation
Predicates transform ation engine
AADL
AADL components repository
Generation
Rules
Stood
Plugins
Reverse
Rules analyser
SIF file transform ation engine
Reverse
Predicates

Use Case 1
AADL Modeler
Stood AADL

AADL Modeler
• UML 2.0 structure diagrams front end
• HOOD design rules:
– visibility rules
– information hiding (i.e. for ports)
– immediate C, Ada, ... and doc generation
• AADL 1.0 generator
• AADL 1.0 semantics checker
• AADL 1.0 code generation rules

AADL
"bridging the gap"
Stood Code

"bridging the gap"
• using AADL as a System to Software bridger
• importing AADL 1.0 specifications
– to be developed with other AADL compliant tools
– preserving the System architecture
• standard Software development process
– SW architectural design refinement
– SW detailed design and documentation
– SW coding and round-trip engineering
• using the AADL output again for V&V
– checking System to Software compliancy
– connecting to external Verification tools (i.e. Cheddar)
– implementing the COTRE annex

Code
reusing legacy systems
Stood AADL

Reusing legacy systems
• a three steps process:
– Ada or C legacy code reverse engineering
– architecture adjustments at SW design level
– AADL generator
• benefits:
– let existing source code components be made visible for new systems at high level
– building non proprietary format component libraries
– facilitating reuse of specialized building blocks

• promotes Model Driven Engineering: « designing before coding »
- advanced modeling solution
- model transformations
• promotes Component Based Architectures to ease:
- team development
- reuse
- testing
- maintenance
• promotes
Flexible Software Design practices:
- incremental documentation
- incremental coding and round-trip engineering
- incremental requirements traceability
- extensive tool customization capabilities

• Software method projects
• STOOD is used on many projects
• Involved with Universities and colleges
•Special offers for Academia

QSEE-Superlite
• Integrated Meta-modeling environment
• Supports many modeling techniques
•UML, DFDs,ERDs,XML Schema models
• Syntactic and Semantic rule enforcement
• Code generation
• Ideal for academia – low cost deal

• AADL 1.0 & UML 2.0 compliant version of Stood
5.0 is NOW available for industrial use
• Download it: www.tni-world.com