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Cambridge University Press 2011

The system life cycle66

Answers to Revision questions: 6 The system life cycle 1Cambridge IGCSE Computer Studies

Below each answer there is a page reerence or the coursebook. Tis is there to help you ocus

your revision. I you nd that you get an answer wrong, you can use this guide to return to the

coursebook to revise the areas that need some extra attention. Please notethese are example

answers only and do notrepresent the only possible answers.

1 Te stages o the systems lie cycle are:

act nding

easibility study

analysis

design

building and testing

documentation

implementation (changeover)

evaluation

maintenance.

See Overview on page 117.

2 A sports club wants to use a database to store membership details.

a Te sports club should collect data about the members: names, addresses, phone numbers,

dates o birth (i relevant).

b When designing a screen layout or data entry, you should take into account the logical

order o asking or inormation and the layout o a paper orm i there is one.

c A possible screen layout would be:

itle Surname

Date o birth (dd/mm/yyyy)

Address

Postal code Phone number

First name

See Input screens on page 129.

3 A supermarket has decided to change rom a manual order-processing system to a

computerised one.

a Fact nding methods that should be used are observation o current procedures, interviews

and inspection o documents. Questionnaires could also be used in some instances.

See Fact nding on page 119.

b Te staff may be trained to use the new system by classroom training or using computer-

based training (CB). In classroom training the staff are the students and a tutor is brought

in to train them on the new system. Tis is useul because it allows questions to be asked

and answered immediately. In CB, each staff member gets a DVD with the training on itso they can learn at their own pace.

See Training on page 140.

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Cambridge University Press 2011 Answers to Revision questions: 6 The system life cycle 2Cambridge IGCSE Computer Studies

4 A solution should be accompanied by technical and user documentation.

See Documentation on page 136.

5 a Treetasks in analysis are act nding, creating a requirements specication and dening

the ow o data through the system.

See Analysis stage on page 122.

b Programs should be tested with extreme and abnormal data, as well as normal data.See page 134.

c Te new system might require corrective maintenance (xing sofware errors or bugs),

adaptive maintenance (to reect changes in the organisations requirements) or perective

maintenance (ways to improve the perormance o the system).

See Maintenance on page 144.

6 a Te three types o test data used in a testing strategy are normal, extreme and abnormal data.

b I a value should be between 0 and 100 inclusive, examples o test data are:

normal: 28 and 79

extreme: 0 and 100 abnormal: 1 and 110.

See page 134.

7 Four methods o system implementation are direct, phased, pilot and parallel running.

a Direct implementation is most suitable when a system is small and not critical to business

running.

b Phased implementation is most suitable when the system can be divided into distinct phases

that do not directly impact on each other.

c Pilot implementation is most suitable when a small part o the business, such as a branch,

can be operated independently rom other parts.

d Parallel running is most suitable when data is critical to the business and it can be evaluated

over a short time.

See Implementation (changeover) stage on page 140.