configuration management Introduction

1. SPM-UNIT IV
CONFIGURATION MANAGEMENT
INTRODUCTION
Prof. Kanchana Devi

2. Introduction
Prof. Kanchana Devi
2
 It is one of the fundamental Activity of software
engineering.
 Changes to the requirements drive the design,
and design changes affect the code
 The change process is simple in concept but
complex in detail.
 In order to handle the changes a separate
formal management is required (i. e.)
Configuration Management

3. Need for Configuration
Management
Prof. Kanchana Devi
3
 The very much difficult task in software
development is to fix the problem
 Eg.
 A difficult bug that was fixed at great expense
suddenly reappears
 A fully tested program suddenly doesn’t work
 A developed and tested feature is missing

4. Solution
Prof. Kanchana Devi
4
 Configuration management helps to reduce these
problems by coordinating the work among the
people
 Without Configuration Management many
Problems arises such as
 Simultaneous Updates
 Shared Code
 Common Code
 Versions
 These problems will result in lack of control, waste
enormous amount of time

5. To have control
Prof. Kanchana Devi
5
 To have a control system that answers the
following questions
 What is my current software configuration?
 What is its status?
 How do I control changes to my configuration?
 How do I inform everyone else of my changes?
 What changes have been made to my software?
 Do anyone else changes affect my software?

6. Software Product Nomenclature
Prof. Kanchana Devi
6
 Control the development of the system
elements and then combined into full system.
System
Sub-
System
Sub-
System
Products
Products
Components
Components
Modules
Modules

7. Prof. Kanchana Devi
7
 System
 The package of all software the meets all user
requirements
 Sub-system
 Communication, display, processing
 Product
 Sub system contain many products
 Eg. Operating system- control program, compiler, ..
 Components
 A control program – supervisor, scheduler, i/o controls
 Module
 Small and self-contained - queue management, interrupt
management

8. Basic Configuration Management
Functions
Prof. Kanchana Devi
8
 Configuration Control
 Revisions
 Derivation
 Versions
 Deltas
 Conditional Code

9. Configuration Control
Prof. Kanchana Devi
9
 The task of configuration control revolves
around one official copy of the code
 The simplest way to protect every system
revision to keep a separate copy of each
revision level
 A good rule of thumb is that “No Separate
Copies of a program can be kept identical”
 Solution: Library Facility
 Eg. Google Excel

10. Revisions
Prof. Kanchana Devi
10
 Keeping track of the revisions is an important
task of configuration management
 When new problems are found, previous tests
can be rerun to trace the problem source.
 Solution: Numbering System

11. Derivations
Prof. Kanchana Devi
11
 The ability is to determine what has changed
is one of the most powerful software testing
aids.
Module 101 Module 101
Control Program level 116 Control Program Level 117
X
Y
Test A Rerun
Test A

12. Some information maintained in
derivation record are:
Prof. Kanchana Devi
12
 The revision level of each module
 The revision level of the tools used to assemble,
compile, link, load and execute the program
 The test cases used and their revision level
 The test data employed
 The files used
 The software and hardware system configuration
including peripherals features options
 The operational procedures

13. Versions
Prof. Kanchana Devi
13
 Several different functions can be
implemented by the same module with only
modest coding differences

14. Deltas
Prof. Kanchana Devi
14
 Use of versions solve the problem of different
functional needs for the same module but
introduce multiple copies of the same code.
MEM
MEMS
MEML
>512
>512
Large Memory
Standard Memory

15. Conditional Code
Prof. Kanchana Devi
15
 Useful for handling slight code variations
 Advantage
 There remains only one copy of the code
 Disadvantages
 Requires the proper parameters to trigger; which
could be astronomical in large systems
 Nightmare to maintain over a decent length of
time.