arcade a formal extensible model based dependability evaluation framework n.
Download
Skip this Video
Download Presentation
Arcade: A formal, extensible, model-based dependability evaluation framework

Loading in 2 Seconds...

play fullscreen
1 / 13

Arcade: A formal, extensible, model-based dependability evaluation framework - PowerPoint PPT Presentation


  • 156 Views
  • Uploaded on

Arcade: A formal, extensible, model-based dependability evaluation framework. Hichem Boudali 1 , Pepijn Crouzen 1,2 , Boudewijn R. Haverkort 1 , Matthias Kuntz 1 , Mari ë lle Stoelinga 1. 1 CS, Twente University, The Netherlands 2 CS, Saarland University, Germany. Motivation/Goals.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Arcade: A formal, extensible, model-based dependability evaluation framework' - yves


Download Now An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
arcade a formal extensible model based dependability evaluation framework

Arcade:A formal, extensible, model-based dependability evaluation framework

Hichem Boudali1, Pepijn Crouzen1,2, Boudewijn R. Haverkort1, Matthias Kuntz1, Mariëlle Stoelinga1

1CS, Twente University, The Netherlands

2CS, Saarland University, Germany

AADL/UML workshop - Belfast

motivation goals
Motivation/Goals
  • Approaches to dependability evaluation:
    • Low level (CTMC, SPN, SPA)
    • Dependability specific (fault trees)
    • Architecture-based (AADL, UML)
  • None is perfect, in terms of:
    • Modeling effort
    • Hierarchy & modularity
    • Expressiveness
    • (formal) Clear semantics
    • Effective solution techniques

Our objective: To devise a formalism that scores high on all these aspects

AADL/UML workshop - Belfast

our solution arcade methodology
Our solution: Arcade methodology
  • Architectural approach (system design)
  • Expressive and extensible
  • Modular modeling
  • Formal semantics (based on I/O-IMC)
  • Efficient state-space generation (compositional-aggregation technique)

AADL/UML workshop - Belfast

what s an i o imc
What’s an I/O-IMC?
  • Combination of I/O automata and CTMC
  • Discrete state space
  • Markovian transitions
  • Interactive transitions
  • Action signature
    • ? - Input actions
    • ! - Output actions
    • ; - Internal actions
  • Behavior of the system results from the composition of its elements.
  • Well-defined composition operator & bisimulation equivalence (state minimization)

λ

failed!

AADL/UML workshop - Belfast

sketch of the proposal
Sketch of the proposal

Control System

Process 1

Process 2

Dependability

Annotation

(User)

Bus

Processor 1

Processor 2

Result

compositional-aggregation

Dependability analysis

Other analyses

Std. solver

AADL/UML workshop - Belfast

arcade current status
Arcade: Current status
  • Use I/O-IMCs as the underlying formal semantics
  • At an architectural level, we have identified/defined:
    • (1) Basic (physical/logical) components (BC)
    • (2) Repair units (RU)
    • (3) Spare management units (SMU)
    • All kinds of behaviors/interactions/dependencies, e.g.:
      • Operational/failure modes
      • Repair and spare management policies
      • Functional dependencies
  • Textual syntax (ultimately graphical and integrate to an ADL)
  • To each component/unit corresponds a pre-defined basic I/O-IMC
  • Use I/O-IMCs’ machinery to carry out state-space generation (compositional-aggregation technique) and analysis

AADL/UML workshop - Belfast

example results
Example & Results

# of states: 98,056

# of transitions: 411,688

Unavailability (50 hours): 6.52100 ∙10-10

Unreliability (50 hours): 52.92420 ∙ 10-10

AADL/UML workshop - Belfast

arcade tool chain
Arcade: Tool chain

AADL/UML workshop - Belfast

arcade a summary
Arcade: A summary

Architectural Dependability Evaluation with Arcade. Dependable Systems & Networks (DSN 2008), Anchorage, Alaska, USA.

  • Low modeling effort:
    • High level & Graphical
    • Standard features (BC, RU, SMU)
    • Tight to an ADL (alternative to AADL error annex)
  • Expressive/Extensible
    • Standard features, but also (well-structured) user-defined features
  • Formal semantics (I/O-IMCs)
  • Compositional & efficient SS generation
  • Hierarchical modeling

AADL/UML workshop - Belfast

extra slides
Extra slides

AADL/UML workshop - Belfast

arcade example 2
Arcade: Example 2

AADL/UML workshop - Belfast

the state space battle
The State-Space Battle
  • Defined and used the I/O-IMC formalism to describe the semantics of each DFT element.
  • I/O-IMCs: CTMC + I/O transitions.
  • Semantics of the entire DFT arises naturally as the composition of its elements’ semantics.
  • Used the compositional-aggregation approach to combat the state-space explosion problem.
  • Lifted the restrictions  extended DFT formalism.

AADL/UML workshop - Belfast

the state space battle1
The State-Space Battle

Translation

Composition +

Hiding

compositional-aggregation

Repeat

Aggregation

(minimization)

Result: System failure probability

Aggregatedsystem CTMC

CORAL

AADL/UML workshop - Belfast