This case study examines the use of 7 quality control tools to improve defect removal efficiency. The current scenario showed high numbers of defects reported across various phases. Analysis identified issues like unstructured internal testing, poor third party testing, and late defect detection. The root causes were determined to be a lack of unit testing, missing review documents, and incomplete requirements. Solutions developed included new testing and review flowcharts, check sheets, and contractual obligations for third parties. Monitoring charts showed defect rates decreased after implementing the solutions. Further control is needed to continually improve efficiency towards a new goal.

1. CASE STUDY
Defect Removal Efficiency
This case study demonstrates the steps of problem solving
using 7 basic quality control tools to solve the problem
By Arti Bhatia

2. STEPS IN PROBLEM SOLVING
1 2 3 4 5 6
Measure Past
Data & Current
State
Identify
Problem
Analyse
Problem
Implement
Solution
Monitor
Solution
Control
By Arti Bhatia

3. MODEL FOR SYSTEMATIC USAGE OF "BASIC QUALITY TOOLS"
By Arti Bhatia

4. CASE STUDY: PROBLEM DESCRIPTION: CURRENT SCENARIO
Suppose you are improving on quality aspects of projects being delivered to improve customer
satisfaction.
The prime goal is delivering projects with minimum defects.
Use 7 QC tools to understand current situation, find root causes, improve requested areas and finally
show process control.
Current Scenario: A group of data analytics team was deployed on collecting defect related data and
following observed things were presented to Higher Management for Month of Mar-19.
Phase Wise distribution of Defects
Defect
Type
Review Testing External Testing
Phases
Requirement
Development
Design Coding
Unit
Testing
Functional
testing
System
Testing
Third Party UAT
Mod A 1 5 1 - 4 1 20 25
Mod B - 6 - 1 6 2 19 20
Mod C - 2 2 2 - - 13 15
Mod D 9 - 0 - 2 1 18 20
Mod E 2 1 - 3 5 - 10 15
Mod F - 4 1 7 - - 10 15
Mod G 5 - 1 1 9 1 27 30
Mod H 6 2 - - 3 1 12 15
By Arti Bhatia

5. CASE STUDY: PROBLEM DESCRIPTION: CURRENT SCENARIO
Defect Trends Data: For period from Jan 17 – Mar 19. As shown in table below:
Month Defects Reported by Internal Teams
Defects Reported by Third Party
Team
Defects Reported by UAT teams
Jan-17 28 60 70
Feb-17 192 57 65
Mar-17 61 23 42
Apr-17 73 45 34
May-17 158 77 61
Jun-17 131 21 25
Jul-17 182 11 15
Aug-17 104 56 56
Sep-17 48 19 21
Oct-17 99 17 20
Nov-17 161 38 38
Dec-17 146 72 72
Jan-18 60 192 200
Feb-18 57 161 201
Mar-18 23 251 202
Apr-18 45 158 155
May-18 77 131 132
Jun-18 21 182 180
Jul-18 11 104 120
Aug-18 56 148 148
Sep-18 19 99 278
Oct-18 17 161 123
Nov-18 38 146 259
Dec-18 72 60 160
Jan-19 34 212 212
Feb-19 85 85 185
By Arti Bhatia

6. CASE STUDY: IDENTIFY PROBLEM: CONTROL CHARTS
By Arti Bhatia

7. CASE STUDY: IDENTIFY PROBLEM: SCATTER DIAGRAMS
By Arti Bhatia

8. CASE STUDY: IDENTIFY PROBLEM: LINE CHART
Decreasing DRE (Defect Removal Efficiency) of internal
testing team
By Arti Bhatia

9. CASE STUDY: IDENTIFY PROBLEM: CONCLUSIONS
A group of data analytics team came up with following observations
1) Summary table of Min, Max and average no. of defects reported between Jan-17 to Mar 19
Data Attributes
Defects Reported by
Internal Teams
Defects Reported by Third
party Teams
Defects Reported by UAT
Teams
Max. No. of Defects Reported 192 251 302
Min. No. of Defects Reported 11 11 15
Average No. of Defects
Reported
76 100 125
2) The control and line charts (DRE) charts from the defect data shows following observations post Dec 17
a) No. of internal defects Reported were less
b) No of Third party reported defects took steep jump
c) No. of Defects reported in UAT also took a steep jump
d) The trends of DRE of third party testing team are not so competitive hence no gain achieved out of them.
3) Conclusions From charts and summary table
The internal team was some what capable to deliver with less defects before Dec 17
Still average no. of defects found in the period were never higher than the external defects found i.e. defect removal
efficiency of internal team was low.
Hence a root cause analysis is to be done so as to find the causes of delivery projects with more no. of defects.
By Arti Bhatia

10. CASE STUDY: IDENTIFY PROBLEM: ROOT CAUSE ANALYSIS
Problem Statement: High no. of defects reported by customer.
High no. of
defects reported
by customer.
Understanding
of Requirements
Unstructured
Internal Review
& Testing
Process
Poort Third
party Testing
Skills of
Resources on
testing & review
Late Detection
of Defects
By Arti Bhatia

11. CASE STUDY: ANALYSE PROBLEM: CONCLUSIONS
The above possible causes were further analyzed using pereto to get major potential causes for the defects.
Defect Distribution based on Causes of Defects
Cause of Defects No of Defects % Of Defects
Internal review and Testing process 120 31%
Late detection of defects 106 28%
Third party testing 77 20%
Skills of resources on testing and
review
54 14%
Understanding of Requirements 24 6%
120
106
77
54 24
0
20
40
60
80
100
120
140
Internal review
and Testing
process
Late detection
of defects
Third party
testing
Skills of
resources on
testing and
review
Understanding
of
Requirments
No.
Of
Defects
Causes of Defects
Graph 2: Case Study: Example for
Pareto
24
120
106
77
54
0
20
40
60
80
100
120
140
Understanding
of
Requirments
Internal review
and Testing
process
Late detection
of defects
Third party
testing
Skills of
resources on
testing and
review
No.
Of
Defects
Causes of Defects
Graph 1: Case Study: Example for
Histogram
By Arti Bhatia

12. CASE STUDY: ANALYSE PROBLEM: CONCLUSIONS
Majority of defects were (80%) contributed because of following:
Cause of Defects No of Defects % Of Defects
Unstructured Internal review and
Testing process
120 31%
Late detection of defects 106 28%
Poor Third party testing 77 20%
Hence Improving in these areas will reduce the reported defects by 80 %
By Arti Bhatia

13. CASE STUDY: ANALYSE PROBLEM: CONCLUSIONS
Further root cause analysis was done on potential causes to get real problems
High no. of
defects reported
by customer.
Internal Review
& Testing
Process
Third party
Testing
Late Detection
of Defects
No unit testing
done Reviews of
modules missing
Review defects
missing for
most of the
modules
Testing defects
missing for most
of modules
High defect
leakage
Defects reported
were tested with
incomplete
requirements
document
Dedicated methods
for review and
testing missing
Missing check
lists
No condition on DRE
in contract agreement
hence high leakage of
defects and poor DRE
By Arti Bhatia

14. CASE STUDY: ANALYSE PROBLEM: CONCLUSIONS
Cause of Defects No of Defects % Of Defects
Internal review and Testing process 120 31%
Late detection of defects 106 28%
Third party testing 77 20%
The real problems clearly shows that
• There is a strong need of improvement in testing & review processes and there awareness.
• Also Laidback behavior of third party testing team needs to be handled
• Proper documentations to be provided to third party team for testing.
• Formal reports to be demanded from them.
The SEPG team came up with solutions and implementation strategy as follows
• Flowcharts and check points (check sheets) for testers and reviewers
• Improvement in testing and review processes
• A methodology to collect and report defects using automation tool
• To have contractual obligation for third party testing in case of Low DRE from them.
Based on Cause and effect diagram a team from SEPG was allocated for improving the processes and awareness on them.
By Arti Bhatia

15. CASE STUDY: SOLUTION TO PROBLEM: FLOWCHARTS
By Arti Bhatia

16. CASE STUDY: SOLUTION TO PROBLEM: CHECK SHEETS
Verification
S.No. Checkpoints Compliance Level Score
1
Are Review/ Verifications procedures and qualification Criteria
established?
Fully Compliant 2
2 Is the type of review identified? Fully Compliant 2
3 Are the reviewer(s) identified? Fully Compliant 2
4 Are the artifacts available for review? Fully Compliant 2
5
Are the identified work products reviewed/ verified as per plans
relevant?
Fully Compliant 2
6 Are all review observations tracked and or closed as applicable? Fully Compliant 2
Validation (SQT)
S.No. Checkpoints Compliance Level Score
1
Is Validation Plan for Product included in IPMP or maintained
separately?
Not In Phase 0
Internal Testing
2
Are work products or product components to be tested/ validated
identified?
Not In Phase 0
3 Are project team members for conduct of validation nominated? Not In Phase 0
4 Is validation environment established? Not In Phase 0
5
Has the criteria and test cases for evaluating compliance been
established?
Not In Phase 0
6 Is internal testing conducted as per test plan? Not In Phase 0
7
Are all issues/ observations recorded, tracked and fix for closure
by relevant stakeholders?
Not In Phase 0
8 Is the test summary report prepared and shared as necessary? Not In Phase 0
External Testing – By Third Party
9
Are work products to be verified and validated by IV&V agency
identified? (Offering Group)
Not In Phase 0
10
Are test cases and qualifying criteria for IV&V testing established,
reviewed and approved?
Not In Phase 0
11 Is the IV&V environment ready? Not In Phase 0
12
Has the IV&V been conducted and test results, observations and
comments recorded and communicated to relevant stakeholders
for closure?
Not In Phase 0
13
Are all observations and comments being monitored and tracked
for closure? (Offering Group)
Not In Phase 0
14 Is the IV&V completed and signed off? Not In Phase 0
15 Is the test summary report prepared and shared as necessary? Not In Phase 0
Acceptance Trials/ User Trials
22
Is the product and team ready as per promulgated Trial
Directives, if applicable?
Not In Phase 0
23
Have the concern agencies been intimated regarding readiness
for acceptance testing?
Not In Phase 0
24
Is the acceptance testing completed and observations, if any,
recorded and forwarded to stakeholders?
Not In Phase 0
25
Are the observations fixed and tracked to closure by relevant
stakeholders?
Not In Phase 0
26 Are the acceptance trials completed and signed off? Not In Phase 0
By Arti Bhatia

17. CASE STUDY: IMPROVE (MONITOR): CONTROL CHARTS
By Arti Bhatia

18. CASE STUDY: IMPROVE (MONITOR): CONTROL CHARTS
By Arti Bhatia

19. CASE STUDY:CONTROL: CONTROL CHARTS
Once the solution is implemented the following things needs to be taken care of:
1. The implemented solution shall be closely monitored
2. Any deviation in expected output shall be subjected to escalation for preventive and/or
corrective actions
3. The controlled solution can be subjected to further improvement by setting continual
improvement goal.
Example in our Case Study : The DRE of internal testing team which was
Fluctuating between 10% to 88 % in period Jan-17 to Mar -19
Has been improved to lie between 73% to 87% in period of Apr-19 to Sep -19
To further control and improve the situation
A new goal to achieve DRE of 92% can be set and plan for same can be put up.
By Arti Bhatia

20. By Arti Bhatia