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Chapter 22, Part 3
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2. SYSTEMS IMPLEMENTATION AND CONVERSION
Systems implementation is the process of installing hardware and software and getting the AIS up and running. These activities are illustrated in Figure 22-3 on page 691.
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4. Implementation Planning:
An implementation plan consists of implementation tasks, expected completion dates, cost estimates and the person or persons responsible for each task.
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7. Prepare Site, Install and Test Hardware:
A large computer may require extensive changes, such as additional electrical outlets, data communications facilities, raised floors, humidity controls, special lighting and air conditioning, security measures such as emergency power supply and fire protection. Space is need for equipment, storage and offices.
Site preparation is usually a lengthy process and should begin well ahead of the installation date.
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8. Select and Train Personnel:
Training often doesn’t get the attention that it should as new systems are rushed into production or sometimes training is an easy thing to reduce when budgets are overstrained
“pay me now or pay me later” – trying to proceed with inadequate training can lead to much higher costs – financial and other
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11. Effective AIS training must consist of more than just hardware and software skills.
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13. Complete Documentation:
Three types of documentation must be prepared for new systems:
1. Development documentation describes the new AIS. It includes:
a system description;
copies of output, input, and file and database layouts;
program flowcharts,
test results; and
user acceptance forms.
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14. Operations documentation includes:
operating schedules;
files and databases accessed;
equipment security; and
file retention requirements.
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15. 3. User documentation teaches users how to. operate the AIS
3. User documentation teaches users how to operate the AIS. It includes a procedures manual and training materials.
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16.   Test System:
Inadequate system testing was one reason for the Blue Cross and Blue Shield system failure described in our text.
Documents and reports, user input, operating and control procedures, processing procedures, and computer programs should all be given a trial run in realistic circumstances.
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17. In addition, capacity limits and backup and recovery procedures should be tested.
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18. Following are three common forms of testing:
1. Walk-throughs are step-by-step reviews of procedures or program logic.
2. Processing test transactions determine if a program operates as designed.
3. Acceptance tests use copies of real transactions and files rather than hypothetical ones.
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22. The text cites the example of Chemical Bank that suffered major consequences of not adequately testing an upgrade to its ATM system.
Customers in New York who withdrew money cash found that there accounts were debited twice. Before the problem was corrected, 150,000 withdrawals with a total value of $8 million were posted to customer accounts.
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23. Even software purchased from an outside vendor must be tested thoroughly before being installed.
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24. Conversion:
Conversion is the process of changing from the old to the new AIS. This includes converting hardware, software, data files and procedures. The process is complete when the new AIS has become a routine, ongoing part of the system.
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25. System Conversion Approaches:
The text suggests four conversion approaches are commonly used to change from an old to a new system:
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26. 1. Direct conversion immediately terminates the old AIS when the new one is introduced. Appropriate when:
The old AIS has no value; or
The new AIS is so different that comparisons between the two are meaningless.
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27. Main advantage to direct conversion:
It may appear to be comparatively inexpensive
Main disadvantage:
It provides no backup AIS.
There is a high risk of failure unless the new system has been very carefully developed and tested.
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28. FOCUS 22-3 on page 693 discusses the problems at Sunbeam Corp
FOCUS 22-3 on page 693 discusses the problems at Sunbeam Corp., in part caused by attempting a direct conversion with no backup system.
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29. Sunbeam used the direct conversion approach to modernize its information system. Unfortunately, the new system did not work. Without any backup system the entire system was down for months. Orders were lost and some customers did not receive their shipments. Sunbeam had to manually bill its customers.
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30. 2. Parallel conversion operates the old and new systems simultaneously for a period of time.
Transactions are processed with both systems, with compared output, reconciled differences, and corrections as needed to the new AIS.
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31. Main advantages to parallel conversion:
It protects the company from errors.
Maintains existing system until such time as new system fully proven allowing reversion and backup if needed.
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32. Main disadvantage:
It is costly and stressful for employees to process all transactions twice.
. Because companies often experience problems during conversion, parallel processing has gained widespread popularity although often it is not possible or deemed not to be possible
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33. 3. Phase-in-conversion gradually replaces elements of the old AIS with the new one. The new system is often phased in a module at a time.
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34. Data processing resources can be acquired over time. Disadvantages:
Main Advantage:
Data processing resources can be acquired over time.
Disadvantages:
Costs of creating temporary interfaces between old and new AIS.
Time required to make the complete conversion.
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35. 4. Pilot conversion implements a system in just one part of the organization, such as a branch location. When problems with the system are resolved, the new system could be implemented at the remaining locations.
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36. Need for interfaces between old and new systems.
Advantages:
Localizes conversion problems and allows training in a live environment.
Disadvantages:
Long conversion time.
Need for interfaces between old and new systems.
The pilot branch or location suffers or benefits ahead of other parts of the organization.
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37. Data Conversion:
Data conversion can be time-consuming, tedious and expensive. The difficulty and magnitude of the task can be easily underestimated.
The first step in the data conversion process is to decide which data files need to be converted. Then they must be checked for completeness and any data inaccuracies and inconsistencies removed. Once the files and databases have been converted and tested for accuracy, the new system is functional.
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38. Data files may need to be modified in three ways:
Files may be moved to a different storage medium (e.g., tape to disk).
Data content may be changed (e.g., fields added or deleted).
A file or database format may be changed.
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40. OPERATIONS AND MAINTENANCE
The final step in the SDLC is to operate and maintain the new system. A post-implementation review should be conducted on a newly installed AIS to ensure it meets its planned objectives.
Table 22-7 on page 694 provides a list of important factors to consider and questions to answer during the post-implementation review.
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42. Any problems discovered during the review should be brought to management’s attention, and adjustments should be made.
When the review has been completed, a post-implementation review report is prepared. The table of contents of this report is provided on page 695.
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44. User acceptance of the post-implementation review report is the final activity in the systems development process.
The text indicates that at this point, work on the new system is not finished. Studies show that over the life of a system, only 30% of the work takes place during development. The remaining 70% is spent on maintaining the system.
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