Chapter 5: Implementing Computer-Based Information Systems

Question 1

Give 3 reasons why it is important the client is involved during the development of a custom-written system?

Answer 1

1. They will provide details of what the new system should do
2. If details are incomplete, the client can expand on the requirements to prevent loss of money and time
3. They can be consulted at all stages to prevent errors

Question 2

What is a cost-benefit analysis?

Answer 2

Analysis of the cost effectiveness of different alternatives to see whether the benefits outweigh the costs

Question 3

In the cost-benefit analysis, give 3 costs that should be considered?

Answer 3

1. Skills and training to learn how to operate the new hardware and software
2. Licences for the new software
3. Hardware needs to be upgraded to meet new requirements

Question 4

Give 2 advantages of off-the-shelf software?

Answer 4

1. Immediately available to install and use

2. Lots of help and support available online from other users

Question 5

Give 2 disadvantages of off-the-shelf software?

Answer 5

1. Not unique and therefore may not meet specific requirements
2. Costs a lot to buy and install on each computer

Question 6

Give 2 advantages of custom-written software?

Answer 6

1. End user owns the software and can sell it to make money

2. Fits the requirements exactly

Question 7

Give 2 disadvantages of custom-written software?

Answer 7

1. Not much support as only the developers will know how to use it
2. Takes a long time to develop

Question 8

What are the 4 installation methods?

Answer 8

1. Parallel
2. Pilot
3. Phased
4. Direct

Question 9

Describe what happens in parallel installation?

Answer 9

The old and new systems are run at the same time. The old is only discarded when accuracy and reliability are confirmed in the new system

Question 10

Describe what happens in pilot installation?

Answer 10

Only selected sections use the new system to build confidence to use it for more and more tasks until they all have been completed

Question 11

Describe what happens in phased installation?

Answer 11

Different systems in the organisation are brought online one by one using the new system until they are all using it

Question 12

Describe what happens in direct installation?

Answer 12

The new system completely replaces the old system in one go

Question 13

Give 1 advantage and disadvantage for parallel installation?

Answer 13

Advantage
1. Problems can be found in the new system and rectified whilst the old system takes over

Disadvantage
1. Data is duplicated so inconsistencies have to be checked twice

Question 14

Give 1 advantage and disadvantage for pilot installation?

Answer 14

Advantage
1. Problems can be found with the new system before the next stages are implemented

Disadvantage
1. Implementing the new system can take a long time

Question 15

Give 1 advantage and disadvantage for phased installation?

Answer 15

Advantage
1. If a problem is found the organisation can still use the old system

Disadvantage
1. Expensive in terms of time and cost

Question 16

Give 1 advantage and disadvantage for direct installation?

Answer 16

Advantage
1. Cheapest in terms of time and cost

Disadvantage
1. Problems may lead to complete loss of data

Question 17

Explain in 3 points, the role of reviews during the life of a computer-based information system?

Answer 17

1. Reviews can be scheduled to occur regularly or with any planned external or internal changes
2. Reviews enable hardware and software developments to be incorporated into the system
3. During reviews users should be asked for views on how well they think the system is working and their feedback noted

Question 18

In role of reviews, what are external changes?

Answer 18

Legislation changes such as TAX and VAT

Question 19

In role of reviews, what are internal changes?

Answer 19

A change in the mode of operation were new functions performed by the system need to be included

Question 20

What are the 3 maintenance methods?

Answer 20

1. Corrective
2. Adaptive
3. Perfective

Question 21

Describe 3 characteristics of the maintenance method Corrective?

Answer 21

1. Also known as remedial maintenance
2. Used if there any errors in the software
3. The bugs can be either programming or logic

Question 22

Describe 2 characteristics of the maintenance method Adaptive?

Answer 22

1. Only occurs when the organisation has a new requirement the system must fulfil
2. Or, the system needs to be adapted due to internal or external changes within the organisation

Question 23

Describe 1 characteristic of the maintenance method Perfective?

Answer 23

1. Only occurs when theres benefits to enhance the performance of the system or to make it easier for the end user to operate

Question 24

Give 1 reasons for the need for Corrective maintenance?

Answer 24

1. Errors not spotted in testing before becomes obvious

Question 25

Give 2 reasons for the need of Adaptive maintenance?

Answer 25

1. Security issues may arise so the system will need more protection
2. New hardware or software may be purchased which needs to be implemented into the system

Question 26

Give 3 reasons for the need of Perfective maintenance?

Answer 26

1. Rewriting procedures to reduce the response time of the system
2. Tasks not included in the design stage need to be added to the system
3. Addition of short-cut keys to help users shorten processes