Post-implementation review Systems maintenance End-user development and user groups

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Post-implementation Issue
Lecture 20
Abdisalam Issa-Salwe
Thames Valley University
Abdisalam Issa-Salwe, Thames Valley University
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Topic list
 Post-implementation review
 Systems maintenance
 End-user development and user
groups

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Abdisalam Issa-Salwe, Thames Valley University
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Post-implementation review
 It should be established whether the
objectives and targeted performance
criteria have been met
 In appraising the peroration of the
new system immediately after the
changeover. It will include:
 Consideration of throughout speed
 Use of computer storage
 The number of type of error/queries
 Cost of processing
Abdisalam Issa-Salwe, Thames Valley University
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Post-implementation review (cont…)
 Report:
 A summary of their finding should be
provided, emphasising any area where the
system has been found unsatisfactory
 A review of system performance should be
provided
 A cost-benefit review comparing the
forecast costs and benefits
 Recommendations to be made as to any
further action or steps which should be
taken to improve performance.

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Abdisalam Issa-Salwe, Thames Valley University
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Systems maintenance
 Types of maintenance:
 Corrective
 Perfective
 Adaptive
Abdisalam Issa-Salwe, Thames Valley University
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Systems maintenance (cont…)
 Corrective Maintenance:
 This type of maintenance refers to changes made
to repair design defects and programming errors.
It usually occurs in the early stage of installation
of the system and they need to correct them as
soon as possible because it may interrupt
company's operations. This type of maintenance
has no extra value or benefit to the system but
merely just to correct defects and errors. This
maintenance is highly performed immediately after
implementation and during the later operational
life.

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Abdisalam Issa-Salwe, Thames Valley University
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Systems maintenance (cont…)
Adaptive Maintenance
 Without a doubt, the system will need
changes due to evolving needs and
requirements. It usually happens in the
mid to late stages of the system. Adaptive
maintenance is not urgently required, but
it provides an improved functionality and
enhancement to the system. This
maintenance is performed during the
early, middle and later operational life.
Abdisalam Issa-Salwe, Thames Valley University
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Systems maintenance (cont…)
 Perfective Maintenance
 Perfective maintenance relates to more
enhancement issues than adaptive
maintenance. For example, a company
may acquire to new version of Windows
and Microsoft Office or improvement
processing performance and interface
designs. Highly performed during the
middle of operational life of a the system.

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Abdisalam Issa-Salwe, Thames Valley University
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Abdisalam Issa-Salwe, Thames Valley University
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Cause systems maintenance
 Errors:
 However carefully and diligently the
systems development staff carry out
systems testing and program testing, it is
likely that bugs will exist in a newly
implemented system,
 Constraints:
 cost constraints may have meant that
certain requested features were not
incorporated

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Abdisalam Issa-Salwe, Thames Valley University
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Cause systems maintenance
 Change in requirements:
 Although users should be consulted at all
stages of systems development, problems
may arise after a system is implemented
because users may have found it difficult
to express their requirement
 Poor documentation:
 If old systems are accompanied by poor
documentation, or even a complete lack of
documentation, it may be very difficult to
understand their programs
Abdisalam Issa-Salwe, Thames Valley University
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Systems maintenance lifecycle
 Corrective and adaptive maintenance should
be carried as and when problem occur, but
perfective maintenance may be carried out
on amore scheduled system-by-system
basis.
 If maintenance requires major changes to
bespoke software, this will involve all the
tasks included in the software development
and testing cycle
 System should be built with certain amount
of flexibility that allows changes to be made
in the future