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define about defect
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Presented by
Deep kumar sharma
M.Tech (1 sem)
04/10/23 1
1. What is Defect Analysis2. Defect Prevention Key Process Area3. Defect Analysis Procedure4. Action Team Activities5. Summary
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• Examination of information about problems• Intent to identify causes of defects so that they can be
prevented or detected earlier Many different approaches called defect analysis or root
cause analysis – employ many different techniques Software
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• Error - a mistake made by a member of the software team• Defect - a section of code or documentation that must be changed
to correct a failure• Failure - a situation in which the software fails to execute as
intended• Problem Report - usually documentation that a failure has occurred
during testing or use. May also be used to document defects found in inspections and reviews.
Software Defect can be defined as “Imperfections in software development process that would cause software to fail to meet the
desired expectations”.
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3.The Defect Causal Chain
Defect(Quality)
Error(Process)
1 + 1 = 3
Failure(Reliability)
PumpingStation
OILCO
Accident(Safety)
OILCO
CausalAnaysisCausal
AnalysisDebuggingDebugging
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CausalAnalysis
ProcessAnalysis
ActionPlanning
ProjectSoftwareProcess
Data
Out of ControlSignal & Data
ProposedAction(s)
CorrectiveAction(s)
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• Assigns responsibility for causal analysis of a process to the software team
• Bases analysis on a sample of problems rather than an exhaustive study of all problems
• The software team proposes actions to:
– prevent problems
– find problems earlier• Assigns responsibility for implementing proposals to a
management action team
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CausalAnalysisMeeting
SoftwareEvaluation
SoftwareProduction
ProblemsIdentified
Software
ActionTeam
Meeting
ProblemDatabase
Sample ofProblems
RecommendedActions
Long-termActions
Problemsto Fix
Organization Process
Short-termActions
Baseline forFuture Projects
Improvement Cycle
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Purpose◦ To identify the cause of defects and prevent them from
recurring KPA goals
◦ Defect prevention activities are planned◦ Common causes of defects are sought out and identified◦ Common causes of defects are prioritized and systematically
eliminated
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Defect prevention is an important activity in any software project. In most software organizations, the project team focuses on defect
detection and rework.. It is therefore advisable to make measures that prevent the defect
from being introduced in the product right from early stages of the project
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Phase KickoffMeeting
CausalAnalysis
Team
ActionTeam
Project Phase (ongoing work)
Defects
SuggestedActions
Process Improvements
Improved ProcessesLessons Learned
Interim ProcessImprovements
Prepared Team
ProcessAssets
DP ActivityPlanning
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• Defines focus, composition, roles, and responsibilities of defect causal analysis team(s)
• Defines charter, composition, roles, and responsibility of action team(s)
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Type of Defect
Nu
mb
er
INTERFACE
DATALOGIC
INITIALIZATION
COMPUTATION
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Type of Defect
Rew
ork
INTERFACE
DATA
LOGIC
INITIALIZATION
COMPUTATION
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• Simple graphical technique• Helps to sort and relate many factors• Developed as a team (facilitated)• Focus for discussion - not a definitive result• Also called an Ishikawa or Fishbone Diagram
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• State problem (effect) - Use statement of Systematic Error - Draw main branch
• Insert headings for generic causes
– methods
– people
– tools/environment
– Input• Highlight principal/operative causes(s) - circle
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Misuse ofComputingEnvironment
Input Methods
People Tools
Lack of
Know
ledge
Lack
of
Con
vent
ions
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• Meets regularly to consider proposed actions • Must include management - needs resources• May include technical personnel • Select and prioritize proposals• Resolve conflicts and combine related proposals• Plan and schedule implementation• Allocate resources and assign responsibility • Monitor progress and effectiveness • Communicate actions and status to the teams
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design code function test system test
Nu
mb
er
of
De
fec
ts
Expected Trend
1.Example of ODC Trend
FunctionAssignmentCheckingTiming
Legend
ODC(Orthogonal defect classification) defect type process signature
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• Most organizations with well-defined processes can benefit from some application of DCA
• Maximum benefit obtained from
– Following a systematic approach
– Involving the developers/maintainers
– Pursuing a strategy derived from an objective understanding of improvement opportunities
• DCA can be applied to any process that receives feedback on its defects or failures
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Ajit Ashok Shenvi,2009,”Defect Prevention with Orthogonal Defect Classification”, In Proc- ISEC ’09, February 23-26, 2009 Defect Prevention by SEI’s CMM Model Version 1.1., http://www.dfs.mil/technology/pal/cmm/vl/dp Linda Westfall, Defect Density Mukesh soni, 1997, Defect Prevention: Reducing cost and improving quality” published in IEEE Computer, (Volume 30, Issue 8), August 1997.
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