chapter 7

Question 1

who is a system analyst

Answer 1

a person who analyses systems.

Question 2

state the 6 stages of the systems life cycle

Answer 2

1. analysis
2. design
3. development and testing
4. implementation
5. documentation
6. evaluation

Question 3

why would a company update its current system

Answer 3

• the existing computer equipment cannot be repaired
• Changes to laws or taxes requiring radical overhaul of software.
  » More suitable hardware is now available to improve efficiency and reliability.
  » There is a need to expand the company.

Question 4

describe what happens during the analysis stage [any4]

Answer 4

» Research the current system
» Identification of input and output
» What processing takes place?
» Problems with the current system
» User requirements for the new system
» What are the information requirements?
» Identify hardware and software for the new system

Question 5

What are the stages of analysis ? [4]

Answer 5

1. Observation
2. Interviews
3. Questionnaires
4. Examination of Existing Documents `

Question 6

describe observation

Answer 6

To watch daily work of personnel
Purpose to get a whole overview to see how the old system works

Question 7

advantages of observation

Answer 7

» it is possible to get an overall view of the system
» inexpensive method as the analyst is only watching the workers
» the analyst obtains reliable data

Question 8

disadvantages of observation [2]

Answer 8

» People are generally uncomfortable being watched and may work differently
» People who violate the rules will not do that if they know they are being watched

Question 9

describe the interview stage

Answer 9

a one to-one question-and-answer session between the analyst and the user

Question 10

advantages of interviews [4]

Answer 10

» Questions can be explained or repeated
» Can change questions in light of previous answers
» The user is more open and honest with the answer
» Interviewer can detect body language and facial expressions

Question 11

disadvantages of interviews [any4]

Answer 11

» Time consuming to interview all the users as the interviews are carried out one at a time [2]
» The interviewee may be dishonest with the questioning as it is not anonymous [2]
» Expensive due to analyst’s time [1]
» Workers may not be available at the time the analyst is available.

Question 12

describe the questionnaire

Answer 12

distributing questionnaires to the workforce, clients or system users to find out their views of the existing system and to find out how some of the key tasks are carried out.

Question 13

advantages of questionnaire [any4]

Answer 13

» The questions can be answered fairly quickly.
» It is a relatively inexpensive method (only need to produce questionnaires)
» Individuals can remain anonymous if they want (therefore give more truthful answers)
» Allows for a quick analysis of the data
» Interviewees can fill in questionnaire in their own time
» Allows a greater number of people to take part

Question 14

disadvantages of questionnaires [any4]

Answer 14

» The number of returned questionnaires can be low; not always a popular method
» The questions are rather rigid because they have to be generic; it is not possible to ask follow-up questions
» No immediate way to clarify a vague answer to a question; it is not possible to expand their answers
» Users tend to exaggerate their responses as they are
anonymous
» Because anonymous, the interviewees may not take it seriously

Question 15

describe the examination of existing documents method/stage

Answer 15

This method allows the analyst to see
1) how existing files are kept,
2) look at operating instructions
3) training manuals
4) check the accounts
This allows the analyst to get some idea of
1) the scale of the problem
2) memory
3) size requirements
4) type of input
5) output devices needed, etc.

Question 16

advantages of examining existing documents [2]

Answer 16

» Can see details of inputs and outputs
» Can understand the flow of data

Question 17

disadvantages of examining existing documents [2]

Answer 17

» Time consuming to go through the documents
» Expensive method as the analyst will have to spend time going through documents

Question 18

why does analyst record and analyze information about the current system ?

Answer 18

» to Identify inputs, outputs and processing of the current system
» to Identify problems with the current system and improvements required
» to Identify the user and information required for the new system

Question 19

what does DFD stand for

Answer 19

Data FLow Diagram

Question 20

what are user requirements and their purpose ?

Answer 20

meaning - written by the analyst for the business in simple words (natural language , no jargon is used)

purpose -
» to enable customers to verify that the analyst’s proposal, based on investigations, aligns with the customer’s specifications.
» describe what the analyst thinks the customer does with their system.

Question 21

what does system specification include

Answer 21

» identify and justify system hardware for the neww system
eg- input and output devices
» identify and justify system software for the new system
eg- operating system, storage, application software

Question 22

what are two ways of having a system software

Answer 22

1) off the self software
2) bespoke software (specially written software)

Question 23

off the shelf software

Answer 23

» Cheaper to purchase as there are no development costs
» More reliable as they only errors will have been located and tested
» Regular upgrades and improvements are more easily obtained
» More support as there are many users

Question 24

Bespoke software(Specially written software)
[2adv 2disadv]

Answer 24

advantages -
» Meets cutomers needs as the software is specially designed for the customer
» Uses less memory as the software only has the feautres needed
» It is easier to use as less functions are there in the software
» Can be changed when the customer needs it changing

disadvantages -
» it will also require considerable training in using software unknown to the employees
» There will be no user base to seek help (they will have to rely on the software development technical team, which could be expensive).

Question 25

Outline the main 4 process in the design stage

Answer 25

» File structures and data structures
» Input formats, including data capture forms
» Output formats, including screen layouts and report layouts
» Validation routines

Question 26

A file is made up of a number of ———-, and each record is broken up into —————

Answer 26

A file is made up of a number of records, and each record is broken up into fields

Question 27

One of the fields must be unique and will act as the ———— field – this is to allow each record to be uniquely identified

Answer 27

One of the fields must be unique and will act as the primary key field – this is to allow each record to be uniquely identified

Question 28

give example of alphanumeric datatype

Answer 28

A345FF or
07432011122

alpha characters (letters
or text) and numeric data (numbers)

Question 29

give example of charecter datatype

Answer 29

X or d

a sinlge letter or text

Question 30

give example of string datatype

Answer 30

example_of_text_
string

string of letters or numbers or other
symbols

Question 31

types of numeric data

Answer 31

integer
decimal/real
currency
date/time

Question 32

define validation

Answer 32

validation is the checking that the data is sensible, reasonable or acceptable and to check if it follows a certain criterion. it is an automatic check carried by a computer.

Question 33

What can validation check (just 2 examples)

Answer 33

a) data is in right type and format
b) within range of possible values

Question 34

describe type check

Answer 34

data is of correct type
ex Letter “A” would not be allowed in a numeric feild

Question 35

describe length check

Answer 35

contains a set of characters
ex candidate number should be 4 digits long.

Question 36

decribe range check

Answer 36

to make sure numbers lie within a specified range (between an acceptable upper value and an acceptable lower value)
ex exam score would range from 1 to 100.

Question 37

decribe format check

Answer 37

data may have a fixed pattern of number of digits and character.
ex a class should in the format of 10c
data - dd/mm/yyyy

Question 38

describe prescence check

Answer 38

existence check

Question 39

describe lookup check

Answer 39

checks that data is one of the possible items in a list

Question 40

describe check digit

Answer 40

extra digit added to a number and calculated from it to make sure that the number is entered correctly to the computer.
e ISBN and barcode validation