Assessing requirements quality through requirements coverage
Download
1 / 10

Assessing Requirements Quality through Requirements Coverage - PowerPoint PPT Presentation


  • 135 Views
  • Uploaded on

Assessing Requirements Quality through Requirements Coverage. Ajitha Rajan University of Minnesota Mats Heimdahl University of Minnesota Kurt Woodham L3 Communications. Properties. Analysis. Testing. Prototyping. Visualization. Code. Model-Based Development. Specification Model.

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 ' Assessing Requirements Quality through Requirements Coverage' - apu


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
Assessing requirements quality through requirements coverage

Assessing Requirements Quality through Requirements Coverage

Ajitha Rajan University of Minnesota

Mats Heimdahl University of Minnesota

Kurt Woodham L3 Communications


Model based development

Properties

Analysis

Testing

Prototyping

Visualization

Code

Model-Based Development

Specification

Model


Model validation problem
Model Validation problem

  • Are the requirements sufficiently defined for the system?

  • How well does the model implement the behaviors specified by the requirements?

We propose a testing approach that explores the relationship betweenrequirements-based structural coverageandmodel-based structural coverage


Are the requirements sufficient
Are the Requirements Sufficient?

Generate to provide requirements coverage

Informal Requirements

Run tests on the model and measure coverage achieved

Measure

Requirements-Based Tests

Model / Design Specification (MUT)

  • Poor coverage of model implies one or more of the following

  • Missing or implicit requirements

  • Behavior in the model not derived from requirements

  • Requirements-based tests are inadequate


Model implements requirements
Model Implements Requirements?

Generate to provide model coverage

Model/Design

Specification

Run tests on the requirements and measure coverage achieved

Measure

Model-Based Tests

Requirements

  • Poor coverage of requirements implies one or both of the following

  • Model does not adequately implement behaviors specified in the requirements

  • Model is correct and requirements are poorly written


Experimental setup
Experimental Setup

  • Requirements Coverage Metric – Unique First Cause (UFC) coverage defined over formal LTL requirements

  • Model Coverage Metric – Modified Condition/Decision Coverage (MC/DC)

  • Four industrial case examples from the avionics domain

  • Two kinds of assessments

    • Generate test suites to provide requirements UFC coverage and measure MC/DC over the model

    • Generate test suites to provide MC/DC over the model and measure UFC achieved over formal requirements.


Experiment results
Experiment Results

MC/DC Achieved by Requirements-Based Tests


Experiment results1
Experiment Results

  • UFC metric “cheated” by the structure of requirements

LTLSPEC G( var_a > (

case

foo : 0 ;

bar: 1 ;

esac +

case

baz : 2 ;

bpr : 3 ;

esac

));

LTLSPEC G( var_a > (

case

foo & baz : 0 + 2 ;

foo & bpr : 0 + 3 ;

bar & baz : 1 + 2 ;

bar & bpr : 1 + 3 ;

esac

));


Experiment results2
Experiment Results

Requirements UFC Coverage Achieved by Model-Based Tests


Conclusions
Conclusions

  • Analyzing requirements coverage Vs model coverage provides a promising means of assessing requirements quality.

  • Effectiveness is dependent on the rigor and robustness of the coverage metrics used

    • UFC sensitive to the structure of the requirements


ad