software enginnering

Amity Institute of Information Technology

Software Engineering

Maintenance Process, Maintenance Model

Submitted byAshish 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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• 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



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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.



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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



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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



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The Maintenance ProcessMaintenance 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


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

softwareadaption

(18%)

Fault repair(17%)

functionalityaddition or

modification(65%)


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Model of Maintenance EffortModel 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


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.


Thank You

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