Saturday, March 23, 2013

Using computers to solve problems

Using computers to solve problems

A software house is planning to release a new accounts package for small businesses. The package is designed to do the following tasks:

(i) Print out a bill for each order sent out by the business.

(ii) Print out a payment slip to go with all bills paid by the business.

(iii) Record the details of all the goods bought and sold by the business.

(iv) Keep a record of all stock held, and update this record when goods are Sold or received.

Using computers to solve problems

(v) Keep and update the financial records of the business, e.g. how much money is in the bank, how much is owed to the business, how much is owed by the business, profits, losses etc.

(a) Give four essential items of hardware that would be needed to run this sort of package.

(b) There are both advantages and disadvantages for small businesses in buying packages like this accounts package. State two advantages and two disadvantages, to a small business, of buying a ready made package from a software house, rather than commissioning one for its particular needs.

(c) The programmers employed by the software house have written a user manual to be supplied with the package. Describe three sections that should be included in this user manual and say what benefit the user might get from each of these.

(d) The programmers have also written the detailed program documentation which is kept by the software house. Describe three sections of this documentation and explain why they are included.

CASE STUDY

When designing the Computerized Personnel System of the Case St.udy a feasibility study was carried out. Stat.e four other stages that you would expect to be carried out during the design and implementation of a new computerized system.

The figure on page 191 is a systems flowchart outlining a computerized payroll system.

(a) What are the media used to store files 'A' and 'B'.

(b) On the diagram find and label

(i) A scratch (work) file.

(ii) A master file.

(iii) A transaction file.

(c) Give one reason why the data is sorted in the process labelled 'C' on the diagram.

Programmers often spend more time maintaining programs than writing new ones. Give three reasons why program maintenance is necessary.

CASE STUDY

The diagram below shows one of the menu screens used in the Computerized Personnel System of the Case Study.

Using computers to solve problems2 

The flowchart should show how each input to the menu screen is dealt with. It is incomplete. Complete the flowchart by writing statements from the list below in the correct boxes.

Statements

stop

clear screen

enter choice

update record

view record

start

is input valid?

is command = 1?

is command = 2?

display menu

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What is output by the flowchart below?

A The first number

B The larger number

C The second number

D The smaller number

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CASE STUDY

The tasks that the computer needs to carry out as customers pass through the checkout include:

inputting the code number on each article

printing the description and price on the receipt

finding the total of each customer's purchases calculating the change required

keeping a total of all the cash taken at the till

updating the stock file

Arrange these tasks (together with any other tasks you consider necessary) in the order in

which they should be done, indicating any groups of tasks that need to be repeated. You may find the use of a system diagram or flowchart useful.

A computer program is to be written using the following flowchart. Dry run the flowchart and write down all the output produced.

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(a) What do the following flowchart symbols stand for?

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(b) Explain why flowcharts are used in computing.

(c) What is the difference between a program flowchart and a system flowchart?

A flow diagram is often a part of program documentation. Give one reason why.

Tick three items which would be found in the user documentation of a word processing package.

item

Found in documentation tick (√)

What commands to use to carry out functions

How to touch type

How to load the package

Examples of screen layout

Program lists

How data moves round the CPU

Instructions about how to 'run' a piece of software are found in the

A Program flowchart

B Program listing

C Sales information

D User manual