Timed Test Cases Generation Based on MSC-2000 Test Purposes

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Timed Test Cases Generation Based on MSC-2000
Test Purposes

• Abdeslam En-Nouaary and Gang Liu
• Department of Electrical and Computer
  Engineering
• Concordia University
• Montréal, Québec, Canada
• November 2, 2004

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Contents

• Introduction
• Overview of Conformance Testing
• Our Approach for Timed Test Cases Generation
  Based on Test Purpose
• Conclusion and Future Works

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Introduction

• What is a real-time system ?
• - A system whose behavior is time dependent.
• - Example air traffic control, monitoring
  medical device, multimedia
  applications.
• Some characteristics of real-time systems?
• - real-time systems have complicated behaviors
• - failure could cost lives and huge economy
  damage
• - too much test cases generated by existing
  algorithms
• - Testing both actions and their time constraints

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Overview of Conformance Testing
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Main Operations of Our Approach

• Four Phases
• - Conversion of MSC test purpose into TIOA.
• - Synchronous product construction
• - Sampling
• - Test cases generation

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FrameWork--- 1st Variant
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Timed Input Output Automata(TIOA)

• A Timed Input Output Automata (TIOA) is a tuple
  (I, O, L, l0, C, T), where
• I the set of inputs.
• O the set of outputs.
• L the set of locations.
• l0 the initial location.
• C the set of clocks all initialized to 0 in l0.
• T the set of transitions.

A 2-Clock TIOA
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Problems Related to Testing TIOA

• Executability of test cases.
• Infinity of time domain.
• Fault Model.
• Fault coverage.
• Conformance relation.

A 2-Clock TIOA
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Message Sequence Chart(MSC)

• A MSC is a structure
• M (P, S, R, A, O, T, Tx, Y), where
• - P is a finite set of instances
• - S is a finite set of sending Message events
• - R is a finite set of receiving message events
• - A is a finite set of local events
• - O is ordering of S,R and A
• - T is set of timers
• - Tx associates each timer related event with its
  timer
• - Y associates each pair of dependent events with
  its timing restriction and duration

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Converting MSC to TIOA

• SIMPLE MSC assumptions
• Received Msg and Send Msg -gt Input and Output in
  TIOA
• Create initial location and final location
• For each event -gt create a destination location
• Each event is converted to a transition
• Time constraints -gt clocks and guards

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Clock Minimizing
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Synchronous Product Construction
specification
Test Purpose
Synchronous Product
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Sampling Grid Automaton
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Traversal Test Cases Derivation
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FrameWork--- 2nd Variant
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Sampling First
GA of specification
GA of Test Purpose
Synchronous Product of GA
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Sampling with Different Granularities
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Conclusion and Future Works

• Conclusion
• - an integrated process is provided
• - solves time related problems
• - less test cases generated than other methods
• Future Works
• - extend the approach to a general form of MSC
• - multi instances (processes) included
• - test cases expressed as Tree and Tabular
  Combined Notation (TTCN)