TOKYO ELECTRON SOFTWARE TECHNOLOGIES 1/5 IWFST Testing & Quality – Issues on implementation quality in our project Nov 8, 2005 Tokyo Electron Software Technologies Ltd. Hidekatsu Matsuda

TOKYO ELECTRON SOFTWARE TECHNOLOGIES 2/5 Overview of our project Developing GUI screen programs for semiconductor manufacturing equipment. Language: C++ More than 100 screens. Total 550KLOC. Team of engineers. Engineer Profile: –Experience on software development:1 to 15 years. Average 8 years. –Experience on OOD / C++:1 to 6 years. Average 3 years.

TOKYO ELECTRON SOFTWARE TECHNOLOGIES 3/5 Defect classification by injected phase In our project, 38% of defect has been injected in implementation phase. Type of errors: -Incorrect conditional logic -Access to deleted object -Memory leak -Lack of error handling -Etc,…

TOKYO ELECTRON SOFTWARE TECHNOLOGIES 4/5 To reduce defect injection in Implementation phase… We tried to introduce source code inspection, but it didn’t work because: –Under tight development schedule, design phase tended to delay, resulting shortened implementation time. This makes engineers reluctant to try new and time-consuming practices. –Everybody knows that code inspection is one of the “best practices”, but are not sure the degree of its positive impact in their own project. Best practices are easy to understand but difficult to promote in real project without showing their positive impact to engineers using example or data from their own project. It would be nice if we have easy-to-use models that can show the impact of best practices to software engineers.

TOKYO ELECTRON SOFTWARE TECHNOLOGIES 5/5 Measuring implementation quality We refactored one of a module to measure the result using several metrics. Improvement by the refactoring was not very obvious by the metrics. Are there more practical metrics? Metric OriginalRefactored OverallPer ModuleOverallPer Module Number of modules22 73 Lines of Code McCabe's Cyclomatic Number Lines of Comment Information Flow (Square(Fan-in * Fan- out)) OriginalRefactored Max CBO (Coupling Between Objects)1320 Average CBO Max Information Flow Average Information Flow