LIM, MARYLYN GRACE C.

OOA

            Book: Systems Analysis and Design: an Active Approach

            Author: George M. Marakas

            Reference No.: QA

                                    76.9

                                    S88

                                    M37

                                    2001

Chapter 13: Implementing and Maintaining the System

Quote: “There are 2 ways of implementing a software design; one way is to make it so simple that there are obviously no deficiencies and the other way is to make it so complicated that there are no obvious deficiencies.”

Review:

            This chapter is the last topic of systems analyst and design. After designing the system internals, we are now going to do the final step which is the implementing and maintaining the system. First, we should know what system implementation is. System implementation is an activity that focuses on ensuring that the new system is functional and operational.

            The process of system implementation is divided into 3 categories of activities. 1.) Application testing and user acceptance. During the implementation process, testing activities are carefully performed to insure that every aspect of the new system has been checked and rechecked. The acceptance testing is use by end users to verify that the delivered and installed product is ready to be put into production use. 2.) User training and final documentation. This is where the final update of the documentation happens. The documentation is intended to provide the users and administrative with the information they need to operate the system. 3.) System installation and conversion. This refers to the activities and processes connected with replacing the existing system with the new system.

            What is post implementation activity? Post implementation activity is the single most costly phase of activity in the life-cycle-approach to systems development. Its primary objective is to correct errors or faults in the system, provide changes to effect performance improvement or to adapt the system to changes in the business environment.

            After implementing the new system, it’s now time to maintain it. There are 4 categories in systems maintenance. 1.) Corrective. This involves fixing bugs and logic errors that were not detected during the implementation testing period. 2.) Adaptive. This involves modifying existing functions or adding new features to accommodate the changes in the business environment. 3.) Perfective. This involves changes made to an existing system that are intended to improve the performance of a function. 4.) Preventive. This involves activities that intended to reduce the chances of a system failure or to extend the capacity of an existing system.