1. © 2003 IBM
Corporation
Why did the Tower of Babel fail?
Siva Prasanth Rentala
IBM-General Motors-WWP,
Bangalore
BCOZ of language confusion and
no Business Process Modeling,
Management, and Engineering
(BPMME) like Software
configuration management
usage

2. Configuration Management
© 2003 IBM Corporation
Why did the Tower of Babel fail?
The Tower of Babel project failed because of lack
of communication and organization.

3. Configuration Management
© 2003 IBM Corporation
"Now the whole earth had one language and few
words. And as men migrated from the east, they
found a plain in the land of Shinar and settled there.
And they said to one another, 'Come, let us make
bricks, and burn them thoroughly.' And they had
brick for stone, and bitumen for mortar. Then they
said, 'Come, let us build ourselves a city, and a tower
with its top in the heavens, and let us make a name
for ourselves, lest we be scattered abroad upon the
face of the whole earth.'
And the LORD came down to see the city and the
tower, which the sons of men had built. And the
LORD said, 'Behold, they are one people, and they
have all one language; and this is only the beginning
of what they will do; and nothing that they propose
to do will now be impossible for them. Come, let us
go down, and there confuse their language, that they
may not understand one another's speech.' So the
LORD scattered them abroad from there over the
face of all the earth, and they left off building the
city.' Therefore its name was called Babel, because
there the LORD confused the language of all the
earth; and from there the LORD scattered them
abroad over the face of all the earth."

4. Configuration Management
© 2003 IBM Corporation
Contents
Characteristics of Today’s Software industry
SCM Concepts and terminology
Why Software configuration management?
Requirements of Configuration management
Standard reports
Typical Uses of SCM

5. Configuration Management
© 2003 IBM Corporation
The Fundamental Law of Configuration
Management
Configuration Management is the
foundation of a software project.
Without it, no matter how talented the
staff, how large the budget, how robust
the development and test processes, or
how technically superior the
development tools, project discipline
will collapse and success will be left to
chance. Do Configuration Management
right, or forget about improving your
development process.

6. © 2003 IBM
Corporation
Today's Software industry
characteristics are..

7. © 2003 IBM
Corporation
Characteristic 1 -
Coordination & Communication
Men and months cannot be interchanged
Fred Brooks
• Number of communication channels
increase exponentially with number of
team members - the number of
coordination problems also increase
exponentially with the project size.

8. Configuration Management
© 2003 IBM Corporation
Communication Channels

9. Configuration Management
© 2003 IBM Corporation
# Team Members #Communication Channels
1 0
2 1
3 3
4 6
5 10
….. …..
n n*(n-1)/2

10. Configuration Management
© 2003 IBM Corporation
Characteristic 2 -
Software is Easy to Copy
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11. Configuration Management
© 2003 IBM Corporation
Characteristic 3 -
Changes
• Different users / customers have different
requirements
• Get clarified / known at a later date
• Changes to business environment
• Technology change
• Personnel whims

12. Configuration Management
© 2003 IBM Corporation
Characteristic 4 -
Personnel Turnover
• Developers leave
• Users change
Further Adds to the Coordination problem

13. Configuration Management
© 2003 IBM Corporation
Resulting Problems
• Listing seems OK; program does not work
• Works in Pune, misbehaves in Detroit.
• We had customized for this client, how do we
install the upgrade now?
• I had fixed this bug last month. How did it re-
appear?
• I haven’t changed the program. Why is it now
blowing up?
• Which is the latest source? I need to put a
patch.
• In the last month, the user asked for this change
and now she does not want it
• Where did Gates leave the programs he was
working on?

14. Configuration Management
© 2003 IBM Corporation
Main Classes of Problems
• Double maintenance problems
• Shared data
• Simultaneous update
• Missing / unknown version problem

15. Configuration Management
© 2003 IBM Corporation
Double Maintenance
• Multiple copies of same software in use
• Fix in one
- SHOULD FIX IN OTHERS
• Example
- Same set of common routines in two systems
- Same system - multiple sites
• forget to inform
• sites detect bug at same time and “fix”
differently
• = = > > DIVERGENCE
• Should do
- Bug fixed in all copies
- Fix same bug in identical manner in all copies

16. Configuration Management
© 2003 IBM Corporation
Shared Data
• Changes made in one program interfere with proper
functioning of other program
- Example : subroutines, MW objects
• Need
- Control of modifications
- Good communications

17. Configuration Management
© 2003 IBM Corporation
Simultaneous Update
• One module being worked on by more than one
programmer
- Changes made by one programmer disappear
• Need
- Better division into modules
- Ensure simultaneous working

18. Configuration Management
© 2003 IBM Corporation
Missing / unknown Version
problem
• Consciously decide which version to keep, which to
destroy
• Use a systematic method to identify versions and
changes across versions
• Use consistent back-up procedures
?

19. Configuration Management
© 2003 IBM Corporation
Why Software Configuration
Management
• SCM addresses all these issues!!
AbracadabraAbracadabra

20. Configuration Management
© 2003 IBM Corporation
SCM provides visibility into the status of the
evolving software product.
SCM answers the following: Who, What, When,
and Why.
 Who made the changes?
 What changes were made to the software?
 When were the changes made?
 Why were the changes made?
Who will benefit from SCM(Importance in
descending order) :
 Software developers
 Project managers
 Quality Assurance (QA) personnel
 Testers
 Customer

21. Configuration Management
© 2003 IBM Corporation
Program Families &
Configurations
A
D
E
B
C
F
A
CLIENT-1
D
G
B
W
E
F
CLIENT-2
Applications
Applications

22. Configuration Management
© 2003 IBM Corporation
A
D
E
B C
F
G
W
CLIENT-A
A
B
C
D
E
F
CLIENT-B
A
B
D
E
F
G
W
Applications

23. Configuration Management
© 2003 IBM Corporation
SCM
Concepts & Terminology

24. Configuration Management
© 2003 IBM Corporation
Definitions
The arrangement of a computer system or
component as defined by the number,
nature, and interconnections of its
constituent parts
Configuration
The art of identifying, organizing and
controlling modifications to the software
being built by a programming team. The
goal is to maximize productivity by
minimizing mistakes.
Configuration Management

25. Configuration Management
© 2003 IBM Corporation
Configuration Management

26. Configuration Management
© 2003 IBM Corporation
Configuration Identification
The approved documentation or description
that identifies and defines a configuration
item's (CI) functional and physical
characteristics in the form of a specification
or standard, algorithm or code, and interface
control description.
A
B
C
D

27. Configuration Management
© 2003 IBM Corporation
Configuration Control
• Evaluation, coordination, approval or disapproval,
and implementation of changes to configuration
items after formal establishment of their
configuration identification

28. Configuration Management
© 2003 IBM Corporation
Configuration Status Accounting
• Recording and reporting of information needed to
manage a configuration effectively. Includes a
listing of the approved configuration
identification, the status of the proposed changes
to the configuration identification, and the
implementation status of approved changes.
CI = 30
CR = 2
PR = 1

29. Configuration Management
© 2003 IBM Corporation
Configuration Audit
• Verifying the following:
•All required configuration items have been
produced
•The current version agrees with the specified
requirements
•The technical documentation completely and
accurately describes that configuration items
•All change requests have been resolved

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© 2003 IBM Corporation
Requirements of Configuration Management

31. Configuration Management
© 2003 IBM Corporation
CM Requirements
• Identification of Configuration Items
• Establishment of Baselines
• Document control
• Version control
• Management of Workspaces
• Creation of Builds
• Backup & Archival
• Management of Changes to Baseline
Configuration Items
• Status Accounting
• Configuration Audits

32. Configuration Management
© 2003 IBM Corporation
Configuration Items and Baselines
• Configuration Item
- An aggregation of software, documents
and data that is treated as a single entity
in the configuration management process
There are 3 types of CIs:
Baselined – Formally reviewed and agreed
document/source code, which is basis
for, further development. E.g.
Requirement specification document,
design document etc.
Controlled and Managed – Documents
describing the admin and project
Management activities. E.g. Project
management plan, task allocation and
project schedule documents, coding or
GUI guidelines
Controlled – Documents obtained from
the customer which are not managed by
us. E.g. reference technical material.

33. Configuration Management
© 2003 IBM Corporation
 What is Baseline?
- A item that has been formally reviewed and
agreed upon, that thereafter serves as the
basis for further development, and that can
be changed only through formal change
procedures

34. Configuration Management
© 2003 IBM Corporation
Configuration Items & Baselines -
Typical Scenario
• Definition Baseline - Created at the end of
Requirement Specifications. Typical
configuration items (CI) -
- Requirement Specifications
- Project Plan
- Design Standards / Guidelines
- Acceptance Test Plan
• Design Baseline - Created at the end of
Design. Typical CIs -
- System Design Specification
- Program Specification
- Data Base Design
- Coding Standards
- System Test Plan
- User Manual
- User Interface Standards
- Testing Standards

35. Configuration Management
© 2003 IBM Corporation
• Code / Unit Test Baseline - Created at the
end of coding and unit. Typical
configuration items (CI) -
- source code
- object code
- unit test data / scripts
• Testing Baseline - Created at the end of
system testing . Typical CIs -
- System test data
- system test scripts
- operations manual
- installation manual

36. Configuration Management
© 2003 IBM Corporation
Definition Baseline Creation - A
schematic
Individual workspaces
Internal review changes
Definition Baseline
Internal review Workspace
Customer Review Workspace
Formal change management
procedures become applicable
Configuration
Audit
Review
Log
Review
Log

37. Configuration Management
© 2003 IBM Corporation
Document control
 Document Control procedure ensures the
traceability of all the documents.
It involves the following tasks:
• Defining the naming scheme.
• Updating Document Record List (DCR) of
the documents to reflect the changes and
assigning of version and release nos.
• Provides usage of the documents by
giving access rights to different folders.
MyName is
Mr.Unique

38. Configuration Management
© 2003 IBM Corporation
Version
 A variant of some artifact; later versions
of an artifact typically expand on earlier
versions.
Version Control
 Version Control ensures the ability to
reproduce any version of the software at
any given time. It controls versions of
source code, executables and
documents .It provides version change
history to ensure trace-ability.
A1
A2
A3A4

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© 2003 IBM Corporation
An operational version of a system or part of
a system that demonstrates a subset of
the capabilities to be provided in the final
product.

40. Configuration Management
© 2003 IBM Corporation
Work space management
 Workspaces refer to ‘private’ areas where
developers can implement and test code
in accordance with the project’s adopted
standards in relative isolation from other
developers.

41. Configuration Management
© 2003 IBM Corporation
 Uncertainty is the only certain in this
world.
Why Backup?

42. Configuration Management
© 2003 IBM Corporation
Change Control

43. Configuration Management
© 2003 IBM Corporation
I can make the change directly in the
baseline copy. Its just a one line
change, so I don’t want to fool
around with Change Request, check-
out, check-in, etc

44. Configuration Management
© 2003 IBM Corporation
Change Control
• Record of changes
• Approval of change requests after analysing
impacts (impact on retest & review, think it
as another proposed)
• Maintaining of baselines
• Traceability between changes and change
requests and vice versa
IEEE Definition
An element of configuration management,
consisting of the evaluation, coordination,
approval or disapproval, and implementation of
changes to configuration items after formal
establishment of their configuration
identification

45. Configuration Management
© 2003 IBM Corporation
Change Management Process
Change request documented
Change request Evaluated
Change request reviewed for approval CCB
approved
Change order prepared
Configuration items, tasks, QC required is
documented
Configuration items checked out
Change made; QC activities carried out
Configuration audit carried out
Changed items carried out
New product release made
Pending rejected

46. Configuration Management
© 2003 IBM Corporation
Change Request
XYZ Software Corp. Change Request
Project: Initiated By: Date:
Description of Change Requested:
Benefits Expected:
Signature of Initiator: Attachments:
Evaluated by: Change Request No.
Technical Impacts:
Estimates for costs and schedule
Signature of evaluator: Attachments
Date:
Approving Auth Signature Date
Recommendations
Change Order Number

47. Configuration Management
© 2003 IBM Corporation

48. Configuration Management
© 2003 IBM Corporation
Change Control Board (CCB)
• Also called Configuration Control Board
• A group of people responsible for evaluating
and approving and disapproving proposed
changes to configuration items, and for
implementation of approved changes.
• Typical CCB members
- Project Manager
- User Representative
- Quality Controller
- Configuration Controller

49. Configuration Management
© 2003 IBM Corporation
Some Good Practices
• Keep version history in the configuration
item.
• Item to contain exact item name, version
number, date
• Identify configuration items to be tracked
• Code should have history in the comment
• Highlight the changes in the document
atleast for two versions.

50. Configuration Management
© 2003 IBM Corporation
Configuration Audit

51. Configuration Management
© 2003 IBM Corporation
Configuration Audits
• To ensure that what has been built is in
conformance with what was required
(original specifications and change requests)
by analysing :
- Test reports
- review reports
- change logs
Definition
Verification of a configuration item’s
compliance with its configuration identification

52. Configuration Management
© 2003 IBM Corporation
Status Accounting
An ounce of derivation is
worth a pound of analysis
- Wayne Babich

53. Configuration Management
© 2003 IBM Corporation
Configuration Status Accounting & Reporting
• Keep track of
- Current identification of items
- Configuration of delivered software
- Status of change requests / problem
reports
- Status of approved changes
IEEE Definition
An element of configuration management,
consisting of the recording and reporting of
information needed to manage a configuration
effectively

54. Configuration Management
© 2003 IBM Corporation
Typical Information
Baseline Library
Items /
Units
Baseline
Units
Release
Release
Units
Change OrderBackup
Backup
Units
Check-in /
Check-out
Change Request/
Problem Log

55. Configuration Management
© 2003 IBM Corporation
Standard Reports
• Summary list Change Requests / Problem
Reports
• List of CR / PR pending approval
• Summary list of Change Orders
• List of Change Orders pending completion
• Items and versions of a Baseline
• Current set of units in the library
• List of changes since Baseline
• List of checked-out items
• History of backups
• History of releases
• List of items / versions in a baseline
• List of items / version in a release

56. Configuration Management
© 2003 IBM Corporation
Typical Uses of the Configuration Accounting
Data
• In which backup is version 1.6 of P13?
• What are the program level changes between
release 5.1 and 5.2?
• Which programs were replaced in release
5.2?
• Which items were changed for Change Order
671? What were the versions of the units
before and after the change? Have all the
changes been incorporated and checked-in?

57. Configuration Management
© 2003 IBM Corporation

58. © 2003 IBM
Corporation
Can we make SCM happen?

59. Configuration Management
© 2003 IBM Corporation
Thank You