maintenance process and model

1. Amity Institute of Information Technology
Software Engineering
Maintenance Process, Maintenance Model
Submitted by
Ashish Kumar

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• The process of modifying a software system or component after
delivery to correct faults, improve performance or other attributes,
or adapt to a changed environment.
• correcting errors found after the software has been delivered.
Software Maintenance

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Types of Maintenance
1. Corrective maintenance:
2. Adaptive maintenance
3. Preventive maintenance
4. Perfective maintenance

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Types of Maintenance
• Maintenance to repair software faults
Changing a system to correct deficiencies in the way meets its
requirements.
• Maintenance to adapt software to a different operating
environment
Changing a system so that it operates in a different environment
(computer, OS, etc.) from its initial implementation
• Maintenance to add to or modify the system’s functionality
Modifying the system to satisfy new requirements

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• Corrective maintenance: Reactive modification of
a software product performed after delivery to
correct discovered problems.(correcting errors)
example: light bulb replacement
Types of Maintenance

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• Adaptive maintenance: Modification of a
software product performed after delivery to
keep a software product usable in a changed
or changing environment(both hardware and
software).
example: websites etc.
Types of Maintenance

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• Preventive maintenance: Modification
of a software product after delivery to
detect and correct latent faults in the
software product before they become
effective faults.(increasing the system’s
maintainability)
example: changing oil & filters
Types of Maintenance

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• Perfective maintenance: Modification of a
software product after delivery to improve
performance or maintainability.(adapting to
changing user requirements)
example: software updates and service packs
Types of Maintenance

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The Maintenance Process
Maintenance process vary considerably depending on the types of
software being maintained, the development processes used in an
organization and people involved in the process.
Change
requests
Impact
analysis
Release
planning
Change
implementation
System
release
Fault
repair
Flat form
adaptation
System
enhancement
Overview of the Maintenance Process

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Factors effect maintenance
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 Lack of documentation
 Lack of time to update existing documentation
 Quality of original application
 Documentation quality
 Rotation of maintenance people
 Different programming styles conflict
 Lack of documentation and tools
 Bad maintenance management
 Documentation policy

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Maintenance effort distribution
software
adaption
(18%)
Fault repair
(17%)
functionality
addition or
modification
(65%)

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Model of Maintenance Effort
Model of maintenance effort M = p + K^(c-d)
• M = total maintenance effort over entire lifecycle
• p = productive efforts: analysis, design, code, test
• c = complexity due to lack of structured design and
documentation
• d = degree of familiarization with the system
• K = empirically determined constant

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Model of Maintenance Effort
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Model of maintenance effort M = p + K^(c-d)
• Cost of maintenance increases exponentially.
• Costs are reduced by structured development
• Costs are reduced by giving the maintenance team time to become
thoroughly familiar with the system

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Software Maintenance Models
 Quick-fix Model
This is basically an approach to maintaining software. It is a fire fighting
approach, waiting for the problem to occur and then trying to fix it as quickly as possible

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 Iterative Enhancement Model
 Analysis
 Characterization of proposed modifications
 Redesign and implementation

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 Reuse Oriented Model
 Identification of the parts of the old system that are candidates for reuse.
 Understanding these system parts.
 Modification of the old system parts appropriate to the new requirements.
 Integration of the modified parts into the new system.

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 Boehm’s Model
• Boehm proposed a model for the maintenance process based upon the economic
models and principles.
• Boehm represent the maintenance process as a closed loop cycle.

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Thank You
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