UNIT 6: EVALUATION AND maintenance – WEEK 10
Before an objective evaluation of the system can be done, the new system that has been implemented needs to monitored. Monitoring is a routine activity in the running of a system. It begins immediately after the system is implemented and continues throughout the lifespan of the system. The results of monitoring will facilitate evaluation and maintenance of the system.
Evaluation is matching the users’ requirements against what has been implemented. After a software goes into operation, the various stakeholders review the system – users, management and the designers to determine if the system has met the original goals set by the project, that is if actual performance matches the clients’ specifications. A key criterion that must be satisfied is whether the implemented system fits the requirements of the client. Actually, evaluation and review take place during every phase to confirm that all the required deliverables for that phase of the SDLC have been achieved before the team proceeds to the phase. At the end of the SDLC, the whole system is also evaluated and any deviations are rectified. Accordingly, it is the outcome of the evaluation that may necessitate maintenance.
The systems maintenance sub-phase begins when a system becomes operational and continues until the lifespan of the system, that is when the system reaches the end of its useful life. Throughout the development process, the objective is to create an information system that is efficient, easy to use, and affordable. After delivering the system, the IT team focuses on support and maintenance tasks to ensure that the system continues to stay aligned with business priorities and continues to run well.
Maintenance expenses vary significantly during the system’s operational life and include spending time and financial resources to support maintenance activities. Maintenance activities include software upgrades, repairs, and fixes of the software if it breaks, changing programs, procedures, adapting the system to changing requirements, and making the system operate more efficiently.
TYPES OF MAINTENANCE
The maintenance work undertaken after the system is implemented can fall into four broad categories:
- Corrective maintenance (performed to fix errors)
- Adaptive maintenance (adds new capability and enhancement)
- Perfective maintenance (improves efficiency)
- Preventive maintenance (reduces the possibility of future system failure)
Corrective maintenance diagnoses and corrects errors in an operational system. To avoid introducing new problems, all maintenance work requires careful analysis before making changes. Any maintenance work that could affect the system must be performed first in the test environment, and then migrated to the operational system. IT support staff responds to errors in various ways, depending on the nature and severity of the problem.
Adaptive maintenance adds enhancements to an operational system and makes the system easier to use. An enhancement is a new feature or capability. The need for adaptive maintenance usually arises from the dynamics of business. Business environment changes such as new products or services, new manufacturing technology, or support for a new web-based operation and it may call for additions to the system.
The procedure for minor adaptive maintenance is similar to routine corrective maintenance. Adaptive maintenance can be more difficult than new systems development because the enhancements must work within the constraints of an existing system.
Perfective maintenance involves changing an operational system to make it more efficient, reliable, or maintainable. Requests for corrective and adaptive maintenance normally come from users, while the IT department usually initiates perfective maintenance.
To avoid problems, preventive maintenance requires analysis of areas where trouble is likely to occur and put in precautionary measures. Like perfective maintenance, the IT department normally initiates preventive maintenance. Preventive maintenance often results in increased user satisfaction.