IMPLEMENTATION AND MAINTENANCE

After the plan for an information system is approved, it’s time to start building it. The implementation phase can include: purchase and install hardware and/or software, create applications, test applications, finalize documentation, train users, convert data, convert to new system.

Application testing is performed in three ways: unit testing, integration testing, and system testing. Unit testing and integration testing are usually performed in a test area. A test area might to be located in an isolated section of storage on the computer system that runs the organization’s regular information system, or might be located on an entirely separate computer system. When a problem is discovered during unit testing or integration testing, the team must track down the source of the problem and correct it. Unit testing and integration testing are then repeated to make sure the problem is corrected, and no new problems were introduced when the original problem was fixed.

The data for a new information system might exist in card files, file folders, or an old information system. This data must be loaded into the new system - a process called “data conversion”. When converting data from a manual system to a computer system, the data can be typed or scanned electronically into the appropriate storage media. When converting data from an existing computer system to a new system, a programmer typically writes conversion software to read the old data and convert it into a format that is usable by the new system.

System conversion refers to the process of deactivating an old information system and activating a new one. It is also referred to as “cutover” or “go live”. There are several strategies for converting to a new system. They are a direct conversion, a parallel conversion, a phased conversion, a pilot conversion.

A new or upgraded information system undergoes a final test called acceptance testing. It includes the use of real data to demonstrate that the system operates correctly under normal and peak data loads. The term “maintenance phase” is a bit misleading because it seems to imply that the information system is maintained in a static state. On the contrary, during the maintenance phase, an information system is likely to undergo many changes to meet an organization’s needs. They can include the following: upgrades to operating system and commercial software, user interface revisions to make the system easier to use, application software revisions to fix bugs and add features, hardware replacements to enhance performance, security upgrades.

To combat an escalating number of viruses, worms, Denial of Service attacks, and intrusions, security has become a top priority for the maintenance phase of an information system’s life cycle. Maintaining security is an ongoing activity. A system operator and a systems programmer are responsible for system maintenance. Even after in-depth training, employees sometimes forget procedures or have difficulty when they encounter a new set of circumstances. Many organizations establish a help desk to handle end-user problems. For example, suppose you encounter a problem with an update procedure and call the help desk. The help desk technician begins to troubleshoot the problem and soon realizes that it is caused by a programming error not caught during system testing. This bug is recorded in a “bug report” that is routed to the programming group, which can determine its severity and take steps to fix it.

Comprehension check. Match the beginnings of the sentences in the first column with the endings in the second.

Vocabulary practice

1. Put the letters in the following words into the correct order.

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2. Fill in the blanks choosing from the variants given.

1. Application testing is performed in three ways: integration testing, unit testing and … .

a) data testing b) program testing c) system testing

2. When a problem is discovered during unit testing or integration testing, the team must … the source of the problem and correct it.

a) investigate b) produce c) include

3. Unit testing and integration testing are repeated to make sure the problem is … .

a) activated b) converted c) solved

4. System conversion refers to the process of deactivating an old … system and activating a new one.

a) information b) operating c) support

5. An information system is likely to undergo many … to meet a company’s needs.

a) changes b) formats c) systems

6. Many organizations establish a help desk … end-user problems.

a) to divide b) to manage c) to enlarge

7. The help desk technician begins to troubleshoot the problem and soon … that it is caused by a programming error not caught during system testing.

a) forgets b) repeats c) understands

3. Match the beginnings and the endings of the instructions/steps given and put them into correct order.

4. Fill in the gaps in the text.

During the ___ phase of the SDLC, the project team supervises the technicians who set up new hardware, install programming languages and other application ___ tools, create and test applications, and customize software. The team also finalizes the system documentation and trains users. In this phase, three types of testing ensure that new software works correctly. ___ testing is performed on each module, and then ___ testing is performed to make sure that all of the modules work together correctly. ___ testing ensures that the software components work correctly on the hardware and with other, perhaps older, elements of the information system.

When application testing is complete, data is converted from the old system to the new one, users are trained, and the new system goes live. Four types of information system “go live” conversions are possible. At the end of the conversion process, the information system undergoes a final test called ___ testing, designed to assure the system’s owner that the new system works as specified.

After installation, an information system enters the ___ phase of its life cycle.

Speaking. Discuss the following questions.

1. Does a new information system typically require new hardware?

2. What the next step in the implementation phase?

3. What is application testing?

4. What documentation does the project team create during the implementation phase?

5. How do employees learn how to use the new information system?

6. How does a business switch from the old information system to the new system?

7. What happens during the maintenance phase?

8. How important is system security during this phase?

9. Who is responsible for system maintenance?

10. Why do maintenance activities include user support?

Critical thinking. Read the article and express your opinion on the problem.

Date: 2015-01-12; view: 985