1. Introduction Problem Demand Solution Implementation Evaluation Summary
Detection Strategies
Metrics-Based Rules for
Detecting Design Flaws
M.... N.....1
1 Universita della Svizzera Italiana, Switzerland
Software Design and Evolution, WS 2009
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Detection Strategies

2. Introduction Problem Demand Solution Implementation Evaluation Summary
Author
Dr. Radu Marinescu
Associate Professor -
Department of Computer Science and Engineering
"Politechnica" University at Timisoara
Author of "Object-Oriented Metrics in Practice"
Nowak Faculty of Informatics
Detection Strategies

3. Introduction Problem Demand Solution Implementation Evaluation Summary
Author
Dr. Radu Marinescu
Associate Professor -
Department of Computer Science and Engineering
"Politechnica" University at Timisoara
Author of "Object-Oriented Metrics in Practice"
Ph.D defense
Mircea Lungu, Today, 17.30, A21, Red Building
Nowak Faculty of Informatics
Detection Strategies

4. Introduction Problem Demand Solution Implementation Evaluation Summary
Outline
1 Introduction
2 Problem
3 Demand
4 Solution
5 Implementation
6 Evaluation
7 Summary
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Detection Strategies

5. Introduction Problem Demand Solution Implementation Evaluation Summary
Metrics
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Detection Strategies

6. Introduction Problem Demand Solution Implementation Evaluation Summary
Metrics
Metrics
ambiguous definitions
noise
relevance
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Detection Strategies

7. Introduction Problem Demand Solution Implementation Evaluation Summary
Metrics
Metrics
ambiguous definitions
noise
relevance
Interpretation
experience based
no model
showing symptoms not a disease
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Detection Strategies

8. Introduction Problem Demand Solution Implementation Evaluation Summary
Strategy
Strategy
"A detection strategy is the quantifiable expression of a rule by
which design fragments that are conforming to that rule can be
detected in the source code"
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Detection Strategies

9. Introduction Problem Demand Solution Implementation Evaluation Summary
Filters
Semantical
threshold value
direction
For example:
Absolute: HigherThan, LowerThan
Relative: TopValues, BottomValues
Statistical
direction
For example: UpperQuantile, BelowMedian
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Detection Strategies

10. Introduction Problem Demand Solution Implementation Evaluation Summary
Strategy
Choosing an appropriate filter
1 Absolute semantical filter
2 Relative semantical filter
3 Semantical filter with percentile values
4 Statistical filter
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Detection Strategies

11. Introduction Problem Demand Solution Implementation Evaluation Summary
Composition
Logical Operators
and, or, butnot
filter Filtered
Metric1
Set1
filter Filtered Composition Rules Final
Metric2
Set2 Results
filter Filtered
Metric3
Set3
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Detection Strategies

12. Introduction Problem Demand Solution Implementation Evaluation Summary
Metrics
"God Class" syndrome.
Weighted Method Count (WMC)
Tight Class Cohesion (TCC)
Access to Foreign Data (ATFD)
(WMC(C), TopValues(25%))∧ (1)
(ATFD(C), HigherThan(1))∧ (2)
(TCC(C), BottomValues(25%)) (3)
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Detection Strategies

13. Introduction Problem Demand Solution Implementation Evaluation Summary
Process
parsing Meta-Model
Sources
(Java, C++)
Metrics using
Detection
Strategy Flaw List
Detection
Manual inspection
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Detection Strategies

14. Introduction Problem Demand Solution Implementation Evaluation Summary
Filter tuning
1 Experience and Literature
2 Reference Samples (Tuning Machine)
3 Evolution Analysis
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15. Introduction Problem Demand Solution Implementation Evaluation Summary
Case-study
Version 1
93 KLOC, 18 Packages, 152 Classes, 1284 Methods
Version 2
116 KLOC, 29 Packages, 387 Classes, 3446 Methods
Evaluation methods
Automatic Classification (differential between the versions)
Manual Investigation (of the Version 1)
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16. Introduction Problem Demand Solution Implementation Evaluation Summary
Summary
Results
Automatic Classification accuracy over 50% with average
over 67%.
Manual Inspection method resulted in Accuracy of 87%.
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Detection Strategies

17. Introduction Problem Demand Solution Implementation Evaluation Summary
Summary
Results
Automatic Classification accuracy over 50% with average
over 67%.
Manual Inspection method resulted in Accuracy of 87%.
Conclusion
Method is very promising !
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Detection Strategies

18. Introduction Problem Demand Solution Implementation Evaluation Summary
Related Work
Quantification of Design Principles and Rules
Using Correlations of Metrics for Design Inspections
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Detection Strategies

19. Introduction Problem Demand Solution Implementation Evaluation Summary
Discussion
Questions and Discussion.
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Detection Strategies