Aircraft Design and an Engineer’s Approach to Software Testing

1. Aircraft Design and an Engineer’s Approach to Software Testing Daniel Böhnke Integrated Aircraft Design Air Transportation Systems

2. Source: Boeing > Aircraft Design and an Engineers Approach to Software Testing > Daniel Böhnke

3. > Aircraft Design and an Engineers Approach to Software Testing > Daniel Böhnke

4. nPax = 140.7 > Aircraft Design and an Engineers Approach to Software Testing > Daniel Böhnke

5. Overview • Conceptual Aircraft Design • An Engineer’s Approach to • Unit • Integration • System • Conclusion & Outlook > Aircraft Design and an Engineers Approach to Software Testing > Daniel Böhnke

6. ConceptualAircraft Design Requirements Simple Methods • Transparency ChangingRequirements • Flexibility Design Concept > Aircraft Design and an Engineers Approach to Software Testing > Daniel Böhnke

7. python VAMPzero.py Requirements Flexibility Calculate Dependencies Transparency Sensitivities Concept > Aircraft Design and an Engineers Approach to Software Testing > Daniel Böhnke

8. VAMPzero Geom Aero … Aircraft Area Component Wing … Parameter Discipline > Aircraft Design and an Engineers Approach to Software Testing > Daniel Böhnke

9. Parameter: Area value • 122m² status • fix • calc • init calc() • Handbook-Methods • otherParameter.getValue() choose replace > Aircraft Design and an Engineers Approach to Software Testing > Daniel Böhnke

10. b/2 = 17m Span² Dependencies AspectRatio= Area 34²m² 9,475 = S = 122m² 122m² vampzero.googlecode.com

11. Unit Testing “[…] the comparison of the unit’s actual behavior with its required behavior as specified in the unit’s requirements documentation.” IEEE Standard for Software Unit Testing > Aircraft Design and an Engineers Approach to Software Testing > Daniel Böhnke

12. Unit Test Plan • Actual Behaviour: • If nPax changes mPayload changes • Required Behaviour: • If nPax changes mPayload changes • If nPax increases mPayload must increase • Check for Sensitivities > Aircraft Design and an Engineers Approach to Software Testing > Daniel Böhnke

13. Finite Differences Complex Step Derivative Sensitivities Error % Step size h > Aircraft Design and an Engineers Approach to Software Testing > Daniel Böhnke

14. Dynamic Typing fromcmathimport … classzeroComplex(complex): def__eq__(self,other): ifself.real == other: return True else: returnFalse > Aircraft Design and an Engineers Approach to Software Testing > Daniel Böhnke

15. Unit Test Data 0 + or - directional sensitivity ++ or - - superior sensitivity +++ or --- largest impact (1 occurrence) < and > bandwidth Inputs Outputs Reference Point Calculated Sensitivities • Integrated Aircraft Design Department • Dependencies • Estimated Sensitivities > Aircraft Design and an Engineers Approach to Software Testing > Daniel Böhnke

16. Unit Test Evaluation • Simple “Regular Expressions” • High Effort • Detailed Insight • Validation & Verification • Is the model implemented correctly? • Does the model return correctly? > Aircraft Design and an Engineers Approach to Software Testing > Daniel Böhnke

17. Integration Testing “Testing in which software components […] are combined and tested to evaluate the interaction among them.” IEEE Standard for System and Software Verification and Validation > Aircraft Design and an Engineers Approach to Software Testing > Daniel Böhnke

18. Integration Test Plan • User overwrites calculations • Actual Behaviour: • If nPax changes mPayload changes • Fails if nPax and mPayload are inputs • Check if input set is over-determined > Aircraft Design and an Engineers Approach to Software Testing > Daniel Böhnke

19. Integration Test If caller.status == ‘fix’ and calles.status == ‘fix’ > Aircraft Design and an Engineers Approach to Software Testing > Daniel Böhnke

20. Integration Test Evaluation • DuringRuntime • Dependent on User Inputs • nearly infinite • from an infinite numberofinputs 99% useless • Not really a test > Aircraft Design and an Engineers Approach to Software Testing > Daniel Böhnke

21. System Testing “Testing conducted on a complete, integrated system to evaluate the system’s compliance with its specified requirements” IEEE Standard for System and Software Verification and Validation > Aircraft Design and an Engineers Approach to Software Testing > Daniel Böhnke

22. System Test Plan > Aircraft Design and an Engineers Approach to Software Testing > Daniel Böhnke

23. System Test Data • Aircraft Characteristics for Airport Planing • Mission Profile • Geometry • Mass Data • Publicly available > Aircraft Design and an Engineers Approach to Software Testing > Daniel Böhnke

24. System Test Data Inputs Outputs Takeoff Mass Empty Mass • Geometry • Speed • Passengers • Engines • Technology Factors > Aircraft Design and an Engineers Approach to Software Testing > Daniel Böhnke

25. 25 aircraft all converge all low indicator for improvement > Aircraft Design and an Engineers Approach to Software Testing > Daniel Böhnke

26. Outlook and Conclusion “An engineer’s approach to software testing does not substitute software testing” Calibration and Validation are closely coupled Applicable for “expert” mathematical software Increases the quality of actual code and development Include system test in release cycle > Aircraft Design and an Engineers Approach to Software Testing > Daniel Böhnke

27. Thanks for Attending !!! daniel.boehnke@dlr.de code.google.com/p/vampzero/downloads/list > Aircraft Design and an Engineers Approach to Software Testing > Daniel Böhnke