Tools for Formal Specifications

1
Tools for Formal Specifications

• Authors
• Alex Kirzhner
• Alex Litvinsky

2
What is Formal Methods

• A specification is defined as an abstract that
  defines what function is provided without
  saying how it will be provided.
• It is a transitional state between requirements
  (that usually written in natural language and
  containing ambiguities) and system design (that
  is presented in form of static state model
  language).

3
Formal Specification devided into

• Model-Oriented
• specification supports the specification of
  systems by construction of a mathematical model
  of the system.

• Algebraic
• used to specify information systems using methods
  derived from abstract algebra or category theory

4
Tools

• The tools that analyzed in this paper are
• BON-CASE tool,
• SCR,
• SpecTRM,
• DOORS,
• CORE

5
BON-CASE Tool

• supports the BON object-oriented modeling
  language
• designed to be extensible for the purposes of
  supporting formal techniques, particularly
  reasoning via lightweight integration with
  existing analytic tools, such as having
  capability of theorem proofing and static
  checkers

6
Bon-Case elements

• Support for formal specification
• Extensible code generation template.
• Single model principle.
• Partially validated metamodel

7
Diagrams and User Interfaces
8
Diagrams and User-Interfaces

• Dynamic Diagrams depicting objects and the
  messages sent between them.
• Use Cases diagrams It supports actors, use
  cases, and basic dependencies between use cases,
  i.e., includes and extends relationships.
• Document generation support for generating
  browsable, understandable documentation for a
  project, its models, and their relationships.
• Code generation --BON-CASE currently supports the
  generation of code in Eiffel, Java, and JML.

9
The abstract architecture of the tool

• A key feature in the development of BON-CASE was
  to provide a framework by which to support formal
  techniques, particularly specification and
  reasoning.

10
SCR Tool

• Introduced in 1995, SCR Tool (SCR) is an
  integrated suite of tools supporting the SCR
  requirements method.
• more than 50 organizations in the US,Canada, UK,
  and Germany, including industrial and government
  organizations as well as universities, are
  experimenting with SCR.

11
SCR tool

• To date, SCR has been applied successfully in
  three external pilot projects
• researchers at NASA's IVV Facility used SCR to
  detect missing cases and unclear concepts.
• Flight guidance system
• Jet Propulsion Laboratory) used SCR to analyze
  specifications of two components of NASA's Deep
  Space-1 spacecraft for errors.

12
SCR tool
13
The SCR Tools consist of

• Specification Editor. To create, modify, or
  display a requirements specification, the user
  invokes the specification editor. Each SCR
  specification is organized into dictionaries and
  tables.
• Dependency Graph Browser Understanding the
  relationship between different parts of a large
  specification can be difficult.
• Consistency Checker The consistency checker
  analyzes a specification for properties derived
  from the SCR requirements model. It exposes
  syntax and type errors, variable name
  discrepancies, missing cases,

14
The SCR Tools consist of(cont)

• Simulator To validate a specification, the user
  can run the simulator and analyze the results to
  ensure that the specification captures the
  intended behavior.
• Model Checker the explicit state model checker
  Spin was integrated into SCR the model checker
  analyzes invariant properties

15
SCR comparing to other tools

• SCR can be distinguished in three major ways
  from other tools
• SCR has a solid mathematical foundation, thus
  allowing sophisticated analyses, such as
  consistency checking and model checking, largely
  unsupported by current tools
• the SCR tools, have a well designed user
  interface, are integrated to work together, and
  provide detailed feedback when errors are
  detected to facilitate their correction.
• users of SCR can do considerable analysis
  without interaction with application experts or
  formal methods researchers, thereby providing
  formal methods usage at low cost.

16
SCR Tool
17
SpecTRM

• a fine tool for safety-critical projects
• is a document-oriented requirement toolset that
  support the specification, design and development
  of safe systems and software
• It can be used for whole system design and
  development as well as design and development of
  separate, independent components
• provides the information, tools, and techniques
  engineers need to identify design constraints for
  system safety during software development.

18
Main Characteristics of SpecTRM

•       Early error detection
•       Traceability
•       Ease of learning, readability,
  reviewability
•       Flexibility
•       Executable models

19
Features of SpecTRM

• Robustness and Determinism assist in consistency
  and completeness analysis
• Robustness checker tries to find cases not
  covered by the requirements
• Traceability is implemented as hyperlinks to
  different positions inside the Intent
  Specification document or to other documents such
  as safety plans and etc.
• Readability and reviewability(easy to learn, only
  a few days needed to get familiar with the tool)

20
SpecTRM

• SpecTRM is written in JAVA,
• it can run on Windows and UNIX, and based on
  framework called Eclipse.
• Eclipse is designed to permit integration of
  tools in one seamless environment.
• SpecTRM can provide a full development
  environment and API for extending SpecTRM with
  custom plugins
• NO import/export capabilities from other
  applications like MSWord, HTML, Excel, and
  others, an effective way for data storage

21
SpecTRM
Screen shot of the blackbox model in SpecTRM
Specification
22
SpecTRM

• SpecTRM is a new and not fully developed tool
• There are a lot of automation capabilities is
  provided by SpecTRM some of them build in, others
  need to be implemented by users or third party
• automatic test generator and code generator are
  the most ask features for this type of tools.

23
DOORS and CORE

• DOORS (Dynamic Object Oriented Requirements
  System) is document-oriented requirements tool by
  QSS Ltd, Oxford, UK
• CORE is an object-oriented requirements tool,
  created by Vitech Corporation, for requirements
  analysis and design automation process.

24
CORE

• CORE trace the requirements to architecture, it
  also provide a lot of visualization via graphical
  representations of your requirements.
• COREsim is a tool for dynamic interpretation of
  behavior model

25
DOORS and CORE

• all or the most of the diagrams are generated
  automatically from requirements.
• it speeds up the process and gives the user more
  clear picture of the component or whole system
  requirements.
• Since DOORS and CORE models can be reverse,
  changes to the model will trigger change in
  documentation.

26
DOORS and CORE features

• executable models,
• advanced traceability,
• checkers
• import/export of documentation
• automatic creation of bi directional links
• DOORS and CORE support specification ownership,
  history of changes and versions (similar to SCM),
  as well as ability to combine with databases for
  data storage

27
CORS and DOORS

• the biggest advantage is multi-user requirements
  management system and remote access to the tool.
• Remote access is done via web browser-based tools
  DOORSnet and CORE2net.
• Change proposals can be submitted on-line that
  will trigger email notification to the
  appropriate people

28
Conclusion

• Among all five tools DOORS and CORE are currently
  among the most used tool in the industry. Both of
  the tools are mature and well developed.
• BON, SpecTRM and SCR are still need some time to
  be fully developed. BON provide a very useful
  and needed feature of code generation from JML,
  but lack reversal of the process.
• The tool that we favor most is SpecTRM, the
  youngest and less mature among others. SpecTRM is
  used SpecTRM-RL with intent specifications to
  incorporate all the functionally that is needed
  for creation of high-quality specification and
  software.

29
References

• 1. BON-CASE An Extensible CASE Tool for Formal
  Specification and Reasoning Richard Paige
  Department of Computer Science, University of
  York, York, U.K.
• http//www.jot.fm/issues/issue_2002_08/article5.pd
  f
• 2. SCR A Toolset for Specifying and Analyzing
  Software Requirements
• Constance Heitmeyer, James Kirby, Bruce Labaw and
  Ramesh Bharadwaj
• Naval Research Laboratory, Code 5546, Washington,
  DC 20375, USA
• http//chacs.nrl.navy.mil/publications/CHACS/1998/
  1998heitmeyer-CAV98.pdf
• 3. Phone and email conversation with Jeffrey
  Howard System Engineer from Software Engineering
  Corporation.
• 4. Making Formal Methods Practical Marc
  Zimmerman, Mario Rodriguez, Benjamin Ingram,
  Masafumi Katahira, Maxime de Villepin, Nancy
  Leveson http//sunnyday.mit.edu/papers/dasc-fm.pdf
  
• 5. Intent Specifications An Approach to
  Building Human-Centered Specifications Nancy G.
  Leveson http//www.safeware-eng.com/pubs/IntSpec.s
  html
• 6. Safeware Engineering Corporation.
  http//www.safewareeng.com, 2003.
• 7. Use of SpecTRM in Space Applications Nancy
  G. Leveson, Masafumi Katahira
• http//sunnyday.mit.edu/papers/masa-issc01.doc
• 8. SpecTRM A CAD System for Digital Automation
  Nancy G. Leveson, Jon Damon Reese, Mats P.E.
  Heimdahl http//www.safeware-eng.com/index.php/pu
  blications/dasc
• 9. Vitech Corporation www.vtcorp.com
• 10. Telelogic Inc. www.telelogic.com
• 11. Interoperability Between the DOORS
  Requirements Management Tool and the CORE Systems
  Engineering Tool (July 2002) Jody Fluhr and Pat
  Macdonald, Vitech Corporation http//www.vtcorp.c
  om/infocenter/CORE-DOORSBridge_2002.pdf

30
Questionsand Comments?????