Defect Analysis
By Vaisali Namburi
Contents
Introduction
Types of Defects
Prevention Techniques
Workflow to improve
Defect prediction models
Defect prevention models
Conclusion
References
Introduction
Defect analysis plays an important role to ensure software quality.
Defects can be injected into the system in any phase of SDLC.
Defect management is a process used to predict and prevent defects.
One hundred percent removal of defects is a myth.
Prevention of defects is better in the terms of cost and time when
compared to detection and removal.
It is estimated > forty percent of time is spent on defect detection
activities.
Types of Defects
1. Function, concerns how the system behaves from customer
perspective.
2. Logic, concerns the functionality of the system.
3. Interface, concerns interactions between components.
4. Checking, concerns the part of the logic that validates and verifies the
data to compute its values might be affected.
5. Assignment, concerns initialization of this variables or blocks might be
affected.
6. Timing or serialization, concerns shared resource management might
be affected.
Prevention Techniques
Defects analysis can be performed using many different techniques,
some of which are very popular and are considered as the basis for any
technique.
1. Orthogonal Defect Classification
2. Root Cause Analysis
3. Defect Pareto Chart
Orthogonal Defect Classification
ODC is a classification scheme, which helps to analyze defects
analytically by extracting critical attributes of the defects.
1. Defect type
2. Defect trigger
3. Defect qualifier
ODC has a framework to categorize defects and the origin of the
defects in the development process.
Integration of ODC in software project reduces the cost and time by
40%.
Root Cause Technique
The first principle helps to find the process or activity that
causes the defect.
Here defects must be analyzed in the early phases of the
development.
The second principle is utilizing local and third party expertise.
Here analysis must be made to identify the cause of the defect.
Experts are hired by an organization to review and analyze the
process so that the defects are mitigated.
Defect Pareto Chart
Chart represents defect types by
frequency.
Defects documented, reviewed, and
analyzed by performing root cause
analysis.
This graph represents these problems
using a bar graph with a curve, which
shows the defects based on their
category.
This helps software developers to
concentrate more on the SDLC phase
that contain more defects, so those
defects can be eliminated first.
Process Improvement Workflow
There are many process models that assist in the successful
development of the software.
Making improvements to the relevant processes may help in preventing
the defect types that are most commonly identified
This helps in reducing the total cost, time, effort and the resources
spent on the software
There are many stages involved in the improvement of the process.
Process Improvement Workflow
Defect Prediction Models
The most time consuming process of a high quality software
development is defect identification and rectification (also expensive).
Prediction Model using Size and Complexity Metrics : Rawat and
Dubey’s prediction model considered size (LOC). Metrics considered for
this approach are complexity and size
Fuzzy Logic Model : Fuzzy Logic is a prediction model described by
Rawat and Dubey, completely based on human behavior.
Defect Prediction Model Based on Six-Sigma Metrics : The six-sigma
based prediction model is a good fit to predict the number defects that
occur in system testing.
Defect Prevention Model
Defects can originate in any phase of SDLC.
Kumaresh and Ramachandran proposed a defect framework that analyzes
the defects that emerged from all 5 phases of SDLC.
Preventive actions for defects are proposed by analyzing the reason for
the occurrence.
They introduced a new metric that counts the number of defects present in
each phase (defect injection metrics)
Defect prevention is a sequential process that helps organizations to
identify and remove defects in a systematic manner.
Defect Prevention Model
Conclusion
Described the importance of defect
development to ensure high quality.
prevention
in
software
Defects classified into categories based on the type of the defect in
order to implement preventive measures.
Defect types that occur frequently are eliminated in such a way that
they do not reoccur.
Defects that cause failure to the system or more damage to the system
must be mitigated when they are observed.
More efficient and effective models must be developed in future to curb
the defects that might lead to the software failure.
References
1. Kumaresh S., Ramachandran B., Defect Analysis and Prevention for
Software Process Quality Improvement, International Journal of
Computer Applications, Volume 8- No.7, October 2010.
2. Kumaresh S., Ramachandran B.,, Defect Prevention Based on 5 Dimensions of
Defect Origin, International Journal of Software Engineering &
Applications(IJSEA).Vol.3, No.4, July 2012.
3. Margarido I. L., Faria J. P., Vidal R. M., Vieira M., Classification of Defect
Types in requirements Specifications: Literature Review, Proposal and
Assessment, Information Systems and Technologies (CISTI, 2011 6th Iberian
Conference (15-18 June 2011, Chaves), 1-6.
References
4. Rawat M. S., Dubey S. K., Software Defect Prediction Models for Quality
Improvement: A Literature Study, International Journal of Computer
Science Issues, Vol. 9. , Issue 5. No.2, September 2012.
5. Trivedi P., Pachori S., Modeling and Analysis of Software Defect
Prevention Using ODC, International Journal of Advanced Computer
Science and Applications, Vol.1, No.3, September 2010.