QW2000 Tutorial C2

Mr. Tom Gilb
(Result Planning Limited )

Requirements Engineering for Software Developers and Testers


Presentation Abstract

A. Narrative Description 40-60% of all software bugs which escape test to the field user have been traced to requirements and design specifications before coding. It has then been proved that Inspecting the specifications sharply reduces this problem. This workshop will explore all aspects of Specification Quality Control in a hands on practical workshop. Participants will actively experience the technology necessary to attack this quality challenge.

B. Learning Objectives. 1. To learn the problem and the solutions mainly by means of personal experience. You will get a series of individual tasks which will teach you basic principles of specification and quality control of specification.

C. Detailed Outline 1. The Ambiguity Test: proving that specifications are unintelligible.

2. Rules: Selecting strong standards for specification which enable quality control.

3. Process Control: Deciding on the economically allowable Major Defect density allowed for a specification to be released to your colleagues

4. Planning: Selecting a suitable sample to check. Selecting checklists. Allocating specialist checking roles on the team. Deciding on checking rates using optimum rate data.

5. Checking: Individual effort to find defects, and especially Major defects.

6. Data Collection: Gathering data on the checking phase: defects, Majors, Rate, Sample size.

7. Extrapolation: Calculating probable team result of unique Major defects/ Logical Page. Calculating total defect density. Calculating defects remaining after corrections {per page, total}. Calculating total future rework costs based on remaining Major defects.

8. Drawing Conclusions: Can the document exit according to our Exit Conditions? If not, what should we do?

9. Observations. What did you learn? What surprised you the most? What do you think you should do back at your own work about these things? What barriers do you see to doing them? What can you do to remove the barriers?

About the Author

Tom Gilb is an independent consultant, teacher and author. He works mainly in UK, Europe and North America. He is resident in Norway.

Tom coined the term 'Software Metrics' with the publication of his book of the same name in 1976 (European edition) and 1977 (USA edition). This work is the acknowledged (by R. Radice and W. Humphrey) as inspiration for much of the Software Engineering Institute's Capability Maturity Model Level 4 (SEI CMM Level 4). His other books include Principles of Software Engineering Management (1988, now in 13th printing) and Software Inspection (1993 with Dorothy Graham). His main professional interest is the development of powerful Systems Engineering methods (covering Requirements, Design, Quality Control and Project Management).