Parameter Dependencies for Component Reliability...

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Parameter Dependencies

for Component Reliability Specifications

Heiko Koziolek (ABB Corporate Research)

Franz Brosch (FZI Karlsruhe, Germany)

Heiko Koziolek: Parameter Dependencies for Component Reliability Specifications 1

EU Project Q-ImPrESS

Quality

Impact

Prediction for

Evolving

Service-oriented

Software

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Software Reliability

Heiko Koziolek: Parameter Dependencies for Component Reliability Specifications 2

“The probability of failure-free operation of a program for a specified period of time

in a specified environment.”[Musa1987]

Architecture-based Reliability Analysis

Heiko Koziolek: Parameter Dependencies for Component Reliability Specifications 3

Markov Model

R = 0.9223

Expected Reliability Markov Model Solution[Trivedi2001]

1

Failure Probability = 0.0022

2

Failure Probability = 0.0012

3

Failure

Probability

= 0.0031

Component Architecture

Problem

Heiko Koziolek: Parameter Dependencies for Component Reliability Specifications 4

How to determine the transition probabilities?

Literature: Existing Approaches

R. Cheung 1980 (IEEE TSE)

• Transition probabilities via measurements

Hamlet 2001 (ICSE)

• Transition probabilities via measurements

Reussner 2003 (JSS Vol. 66 No.3)

• Assumes transition probabilities as given

L. Cheung 2008 (ICSE)

• Assumes no control flow propagation

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Our Solution

Heiko Koziolek: Parameter Dependencies for Component Reliability Specifications 6

Our Solution: Model

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Internal Action

Sequence

External Call

Branch

Branch Probability

Our Solution: Model

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Failure Probability

External

Call

Inputs Input

Parameter

Parameter

Dependency Input

Parameter

Parameter

Dependency

Branch Probability

Our Solution: Model

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Loop

Number of Iterations

Our Solution: Model

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Our Solution: Transformation

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Our Solution: Markov Model Solution

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Q R

[Trivedi2001]

Case Study: Retail Management System

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Case Study: Inventory Service - Book Sale

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Case Study: Modelling

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Component

Architecture

Control Flow Graph

for a Component Service

Parameter Dependency

on Loop Count

Palladio

Tool

Case Study: Analysis

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Markov Model Solution

Palladio

Tool

Case Study: Reliability Prediction Results

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Case Study: Reliability Prediction Results

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Assumptions & Limitations

Markov Property

Failure Probabilities

Determiniation?

Stochastically Independent

Constant

Expressiveness

No Hardware Failures

No Concurrency

No Repair

Getting Parameter

Dependencies

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Conclusion

Parameter Dependencies for

Component Reliability Specifications

Modelling by component developer

and software architect

Easy alternation

of system-level usage profile

Reusable reliability specifications

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