5 System Life Cycle

Question 1

Analysis

objectives

how

Answer 1

objectives: analyze and evaluate diff methods of evaluating a situation (questionnaires, observation, document analysis, interview) + describe content of requirement/system/design spisification
find how current system works
gather requirements for new system

Question 2

analysis > questionnaire

Answer 2

many response
asked in a way to help analyze data 
can be anon. // honest 
close ended q
no elaboration

Question 3

analyssi > interview

Answer 3

one on one / focus group style
in depth 
ask q if unclear 
time consuming 
honesty?

Question 4

analysis > observation

Answer 4

analyst watch the process of existing system
can ask the user about the flow of the system
can first hand experience how it work
user may perform diff (imagine how youre. when a teacher watches your class!)

Question 5

analsys > docuent analysis

adv disadv

Answer 5

analyst check e.g of docs
identify input/ output
input: how data is collected/ processed by system // input form
output: // report

Method is not to be used on its own.
Documents only show output, doesn’t show additional data needed.

Question 6

development and testing

developers
testers
test plan

Answer 6

developers: follow the agreed spis to develop application
testers: use test plan to follow exactly how and what to test the system
…
…
…
create test plan
consider data format, validation types (from data dictionary)
decide what might go wrong /close to extreme / valid common data

Question 7

implementation

Answer 7

parallel
direct
phased

Question 8

3 types of spis

Answer 8

Spisifictaions
Requirement 
contract between developer and client , spis what client need 
purpose objective of system
data stored
data validation 
validation verification 
budget
timeline 
input output data
functional requirement 
client should approve
System  
list of software hardware needed or new system 
usually software first then hardware 
software 
OS requirement 
other system software / database platform 
hardware 
storage requirement
minimum and rec processing and memory 
extra input/output devices 
Design 
how system look /designer 
UI
house style 
storyboard (interaction)
how system work / developer
data dictionary 
system flowchart
data collection forms
screen layouts
validation routine

Question 9

Alpha testing

Answer 9

carried out by the developers or a special team before a system is delivered to users.

Question 10

Beta testing

Answer 10

Beta testing is used when software is being made available to a large number of users. Beta testers would be selected users who test an early release of an application after alpha testing.

Question 11

Black box

Answer 11

involves selecting input data and checking that expected output matches actual output. Involves testing the whole system or user testing. No knowledge of the way the system works is required.

Question 12

White box

Answer 12

involves the same process but the internal structure and logic of the program are known to the tester. Usually takes place with small program modules.

Question 13

parallel

Answer 13

Parallel is when a new and old system is run at the same time.
Advantages: It’s less risky because if the new system fails, the old is always there. Accuracies of both systems can be compared.
Disadvantages: it’s more expensive as more staff required to duplicate data and diff g hardware may be needed
Data might be input differently in both

Question 14

direct/plunge changeover

Answer 14

Direct or plunge changeover is when all the data is moved to the new system.
Advantages: This is a cheap method, the data used will be consistent and the new system doesn’t have to be compatible with the old
Disadvantages: it’s very risky and users would need to be trained in advance.

Question 15

Phased

Answer 15

Phased is when parts of new system are installed one at a time.
Advantages: Errors would only affect one part and users can easily be trained.

Disadvantages: using 2 systems might be confusing and there might be delays waiting for the phase to be successful. Both systems will also need to be

Question 16

Pilot

Answer 16

Pilot takes place when one part of an organisation starts to use the new system and the rest continue with old.
Advantages: Errors will only affect pilot group and the pilot group can train other users.
Disadvantages: the method is very slow, and users might not like to use the new system. Both systems will need to be compatible.

Question 17

documentation

Answer 17

Technical documentation is an overview of the structure of the system, how it was put together, and how it works. It will include a data dictionary to show how data has been structured within the system. It will also include an installation guide, results of testing and detailed backup routines.
It’s needed for people carrying out future maintenance so they can understand how the system is configured

User documentation is user guide giving instructions to the user. It includes details about how to use the system, alphabetical list of technical terms, a troubleshooting section and an index.
Its needed so the user can learn how to use the system and easily troubleshoot.

Question 18

4 types maintenance

Answer 18

Perfective maintenance aims to always look to improve the system even if there aren’t any errors. Adaptive maintenance aims to adapt to changes such as new laws, new organisation etc.
Preventative maintenance aims to prevent problems arising in system. Regular checks like hardware checks are conducted for this.
Corrective maintenance is to correct errors or bugs discovered in the system.