1. Configuration Management
Ch-10
Configuration Management

2. Introduction
A software project produces a number of items during its execution including various documents, manuals, programs, data.
All these items can be changed.
It is essential to manage and control the changes.
Configuration management is also known as software configuration management. It is the aspect of project management that focuses exclusively on systematically controlling the changes that occur during the project
It consists of set of activities performed to identify and organize software items and to control modification
It is also needed to satisfy one of the basic objectives of delivering a high quality software

3. Configuration management concepts
A primary objective of CM is to manage the evolving configuration of the software system
Program’s evolution takes it through many steps
Consider the figure of life cycle of an item

4. Life cycle of an item production baseline private
Ready for acceptance
Testing
private
Defects in acceptance testing
release
production
Programmer satisfied
Defects for unit testing
defects in system testing
System testing complete
On successful release
Ready for unit testing
baseline
Unit testing complete
Ready for system
Testing

5. Give States of programs
This information is needed to decide when to start testing or when to release the software
Give latest version of a program
Handle concurrent update requests
Undo a program change
Prevent unauthorized changes or deletions
Provide traceability between requirement change request and program changes
Undo a requirement change
Show associated changes
Gather all sources, documents and other information for the current system

6. Continue…
The main purpose of CM is to provide various mechanisms that can support the functionality needed to handle the type of scenarios discussed above
The mechanisms commonly used to provide the necessary functionality include the following:
Naming conventions and organization of files
version control
Change request traceability
Access control
Reconciliation procedures
Modification log in programs

7. Dependence graph Concurrent Undo a Get state updates Program change
Prevent
unauthorized
changes
Associated
changes
Undo requirement
change
Modification
log
reconciliation
Naming &
Maintenance
state
Version control
Access control
Change
traceability

8. Configuration management Process
The CM process defines the sequence of activities that need to be performed in support of the CM mechanisms.
At infosys, the main stages in the CM process are as follows:
Plan and set up configuration management
Perform configuration control
Monitor the status of configuration items

9. Plan and Set Up Configuration Management
Planning for configuration management involves identifying the configuration items and specifying the procedures to be used for controlling and implementing changes to these configuration items
Identifying configuration items is a fundamental activity in any type of CM
If team members do not have a clear idea about the items under the control of CM, it will be much more difficult to implement a desired change
Examples of configuration items are SRS, design documents, source code, test plans, test scripts, test procedures etc
During planning, the types of items are identified but detailed list is not prepared

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To facilitate proper naming of configuration items, the naming conventions are decided
Version numbering must also be planned. When a configuration item is changed, the old item is not replaced with a new copy: instead the old copy is maintained and a new one is created. This approach results in multiple versioning
CM process must control the different states of program and transition between those states
One way of collecting items in different states is to create separate directories
All items in a certain state reside in directory for that state
When the state of program changes, that program is moved from the directory for old state to the directory for new state
The planning is done by project leader and the configuration controller (CC)

11. Continue… The activities in this stage include the following:
Identify the configuration items
Define the naming and numbering scheme for the same
Define directory structure
Define access restrictions
Define change control procedures
Identify and define the responsibility and authority for CC/CCB
Define a method for tracking the status of configuration items
Define back up procedure
Define a reconciliation procedure
Define release procedure
Define an archival procedure
Identify points at which the configuration items will be moved to the baseline

12. Continue… The output of this phase is CM plan
CC is responsible for the implementation of the CM activities within the project

13. Perform Configuration Control
There are two main Configuration control activities
Deals with managing the state transitions of programs
Deals with managing the change request that must be implemented
State transition management involves moving the items from one directory to another when the state changes, creating various versions when changes are made and ensuring that each program goes through its life cycle and reaches the baseline
 Once all the items are in baseline, the software is ready for use
 Many CM tools employ the check-in/out procedure for controlling the access and handling version control
A program is considered to be in “controlled environment” when it is in any state in which others can use it. Once it is in this environment it can’t be modified without proper authorization
Checking out implies making a copy of the item, without destroying the earlier one and making a note that item has been

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checked out so that multiple people do not check an item out for modification
The following activities are a part of implementing a change request:
Accept the change request
Set up tracking mechanism
check out configuration items that needs to be changed and perform the changes
Check in configuration items
Take the item through its life cycle

15. Status monitoring and audits
It is important to represent the state of each item as state can lead to problems
For eg if the program has not been unit tested but it is moved to the state “ready for release” then it can cause problems
Whenever a mechanism based on directory structure is used to represent the state of program, mistakes are possible
This requires that the programs be moved properly from one directory to another when their state changes and this change of state be reflected.
In addition to checking the status of items, the status of change requests must be checked
Finally a configuration audit may be performed. The main focus is to ensure that the CM process is followed

16. Document control
In any organization, documents have to be created, distributed and maintained
The two types of documents that needs to be controlled:
Process definition
Project documents
Once created documents have to be reviewed and authorized
Once a document is reviewed and approved, it may be baselined
Even after baseline documents may alter
There are certain rules for controlling changes to documents:
Any change that affects the form, funtion of the document is considered a major change otherwise it is minor
Approval of changes is performed by the same function that performs the original approval
The version number of the next issue is determined by the extent

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Of changes
A revision list is maintained in document itself, giving history of changes made to the document
Document numbering scheme is also recommended so that each document has unique reference number
To ensure consistency, documentation have standards
A documentation standard is a set of guidelines specifying not only the document structure, but also the format of pages, titles, use of font size, styles, section numbering etc.
For eg Infosys standards require that document should include following:
Title page
Revision list
Table of contents
Main body of document
references

18. Continue… Appendices Index
Document circulation requirements fall in one of the following three categories:
Proprietary: circulation is restricted to a defined set of individuals.
a master is maintained, with a set of copies remaining under restricted distribution
Limited: circulation is restricted to the group of individuals whose duties are directly related to the documents
Unlimited: these documents are for general circulation
Copies of any type of document could be either controlled or uncontrolled.
Controlled copies are issued to limited set of people
Uncontrolled copies for a specific reason and are expected to be destroyed after their purpose is fulfilled