Opening The Black Box: An Introduction to Quality Driven Development

Tuesday 25 August 2009, 18:30 (Light refreshments from 17:45)

Tim Hunter MBCS, CITP, PGD CCI (Open), IT consultant for Yorview


‘Black Box’ working is where you have no knowledge of the internal workings of a system. However, how many defects remain undetected due to this problem?

This talk looks at the ‘Black Box’ view of software developments, and uses worked examples to show the things that may be missed unless testers are used who appreciate the underlying complexities of IT. Various ‘Black Box’ problems are examined such as:

  • Lack of control over testing
  • Hidden / unknown functionality
  • Manual processes
  • Compensating errors
  • Incorrect tests and incorrect assumptions

The talk also introduces Quality Driven Development (QDD), a technique which can resolve the Agile / Waterfall debate. QDD establishes a point where a stable release of code is arrived at, and only sets the ‘clock ticking’ on testing time from that point onwards. This is an evolutionary/iterative ‘prototyping’ phase that precedes the formal test stage.

Any testing time up to the stable point being reached is called ‘Development by Test’ Time (DBT). DBT is charged to the project as Development time, not testing time i.e. it is not allowed to reduce the amount of ‘real test’ time. DBT also provides transparency to project sponsors of the quality of the development.

Tim Hunter, our speaker, is an IT consultant for Yorview. He has over 28 years experience of IT development and testing, gained in major companies throughout the UK and Europe. His wide ranging experience includes Project Delivery and System Testing gained in various Financial Services Sectors including Retail Credit, Banking, Insurance and Telecommunications.

After 10 years of running his own IT consultancy, Tim has launched his own Quality Driven Development methodology which he hopes will resolve the Agile / Waterfall debate. He has written articles for Computer Weekly and IT Now. Tim also runs one of the most commented on blogs on the BCS website: the IT Quality blog.

Tim is an experienced speaker, and has delivered speeches at the Software Quality Management Conference (Southampton, UK) and the BCS Software Testing Specialist Group Conference (London UK) in 2009.

View the presentation (PDF)