1. Intelligent Database Systems Lab 國立雲林科技大學 National Yunlin University of Science and Technology Mining Software History to Improve Software Maintenance Quality Presenter : Li Shu-Ya Authors : Alexander Tarvo, Microsoft Software, 2009

2. Intelligent Database Systems Lab N.Y.U.S.T. I. M. 2 Outline Motivation Objective Methodology Experiments and Results Conclusion Comments

3. Intelligent Database Systems Lab N.Y.U.S.T. I. M. Motivation 3 Bug? Update Bug? Upate Bug? Update Alex 專長： 把 bug 越 De 越多 … 專長： Debug Oh! Software Regressions?! Oh! Software Regressions?! I must improve it! I must improve it! A story in Micosoft … King of Garbage 我最會 Debug 了 ( 叫我 king..) 我最會 Debug 了 ( 叫我 king..) King of Destruction 我是破壞王 ( 我也是 king.. 怎樣 ~) 我是破壞王 ( 我也是 king.. 怎樣 ~)

4. Intelligent Database Systems Lab N.Y.U.S.T. I. M. Objectives The best method to avoid regressions’ consequences  extensive testing of all fixes. Need a tool or a method that can predict the amount of risk for each fix. 4

5. Intelligent Database Systems Lab N.Y.U.S.T. I. M. Methodology – System Overview 5 Binary Change Tracer (BCT)

6. Intelligent Database Systems Lab N.Y.U.S.T. I. M. Binary Change Tracer (BCT) 6 1. Dividing the binary into components.2. Extracting the history of code changes 3. Associating code changes with bugs.4. Storing the extracted data Bug tracking databases (BTDs) Check-in IDs in VCS Relate BCT Bugs check-ins Developers Binaries source files functions code complexity Coupling OO metrics MaX

7. Intelligent Database Systems Lab N.Y.U.S.T. I. M. Experiments 7 the best indicators of regression risk source files affected by the fix All functions change a new functionality

8. Intelligent Database Systems Lab N.Y.U.S.T. I. M. Conclusion This model is useful for risk prediction. 8 2009 年 Micosoft 最佳員工獎 還好有這個系統 讓我沒有被裁員 還好有這個系統 讓我沒有被裁員

9. Intelligent Database Systems Lab N.Y.U.S.T. I. M. Comments Advantage  It really improve software maintenance quality Drawback  … Application  Software Maintenance 9