1 SEG4910 – Projet génie logiciel en fin d’études / Software Engineering Capstone Project Review of Quality Assurance Timothy C. Lethbridge Derived from notes by Liam Peyton

2 Increase customer confidence Improve work processes and efficiency  Save time that would be used fixing defects Enable company to better compete Increase management and investor confidence Quality Assurance and Productivity go Together

3 Cost of corrections Req. Design Code Dev. System Field test test Operation

4 Testing White Box Verification  Test-Driven Development, Code and design Inspections, coverage, formal program verification, invariants Black Box Testing  Requirements scenarios, equivalence classes and boundaries  Unit Testing (Junit, HttpUnit, custom code) Architecture-driven Test driver and test data for each component  System Testing (of released executables) End to end, simulated customer environment  Usability Testing  Acceptance Testing “Real” users doing “real” scenarios (test environment)

Inspection Significant changes should have their designs inspected before implementation Every commit should be inspected by multiple people Periodic walk-throughs of entire system 5

6 Example Sources of Defects Misinterpretation of customer/user needs /communication Unanticipated scenarios never accounted for  Changing operating system or regulations, feature interactions Incomplete or erroneous specifications Intentional deviation from specifications Violation of programming or design standards Error in data representation Inconsistent component interface Error in design logic Incomplete or erroneous testing Inaccurate or incomplete documentation Error in programming language translation of design Weakness in user interface

Tracking and continual improvement Have a goal to reduce the number of high priority defects Track over time Remove defects before adding features Data mine for common causes  Improve processes to reduce common causes Show graphs of accomplishments 7