Software Configuration Management

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Software Configuration Management
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SCM

• A discipline for controlling the evolution of
  software systems.
• Has many aspects
• Identification
• Control
• Status accounting
• Audit and review

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Identification

• What are the configuration items? (I.e., what is
  under configuration management?)
• How do you name them?
• What is the relationship between items?
• Versions
• Baseline
• Release

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Versions
V3.1
V3.1.1
V3.1.2
V3
V3.2
V3.3.2
V3.3
V3.3.1
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Baseline

• Baseline is a software configuration item that
  has been reviewed and agreed upon, and that can
  be changed only through formal change control
  procedures
• Intermediate versions that havent been reviewed
  are SCIs but not baselines.

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Release

• Release is a software configuration item that the
  developers give to other people
• Release should be a baseline

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Control

• Who is allowed to read/write configuration items?
• How do you know if changes are allowed/correct?

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Status accounting

• Reporting the status of components and change
  requests
• Which components have changed this week?
• Which components did Bob change?
• Which components have the most changes?
• Which change requests are more than a month old
  and of priority 3 or greater?

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Audit and review

• How do we know that the build script is OK?
• How do we know that only authorized people can
  change the database interface?
• Can we actually run the version from March 3,
  1998?

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Change control

• Change request/engineering change order
• User story
• Bug report
• Change control authority - decides which changes
  should be carried out
• CMS should tie code changes back to change
  requests

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Change control authority

• Change control authority
• determines new features
• determines bugs that will be fixed
• Where is the change control authority
• in XP?
• In RUP?

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Build management

• How do you build the product?
• Which compiler? Which flags?
• Which source files?
• Which libraries should be linked?
• Which also means which version

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make

• The makefile describes
• how to compile
• the source files to use
• the compiler to use
• the compiler flags to use
• how to link
• the libraries to use
• how to install, clean up, print out, test, etc
• No version information!

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Daily build and smoke test

• Ways to break the build process
• check in bad code
• forget to include file in makefile
• move a library
• Every day (night) build the latest version of
  product and run simple test suite

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To make SCM work requires

• Bureaucracy
• Discipline/training
• Tools

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CVS is an example of

• An S.E. tool
• Several activities
• Supported by processes

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CVS

• Records history of source files
• Efficiently records every version
• Helps developers work concurrently

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CVS

• Does not
• Build an executable
• use make
• Keep track of change requests, change orders
• use Bugzilla or GNATS
• Enforce a particular process

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CVS
Developer 4
Repository
Developer 1
Developer 3
Developer 2
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Things to do with CVS

• Get source code
• Put new version back into repository
• Compare differences between versions
• Create, delete, change permissions, etc

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Quiz

• What is the purpose of a tool for
• Version control
• Change management
• Building
• Baseline
• Software configuration item
• Configuration object
• Access control

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First homework

• http//wiki.cs.uiuc.edu/SEcourse/329Homework1
• Setup version control system
• Setup change control policy

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Next time cvs

• Read chapter 1 of the cvs manual at
  http//www.cvshome.org/docs/manual/