Systems analysis and design Flashcards
What are you doing when you are designing how data will be entered into the system?
Designing data entry forms
ICT
Investigation Methods
What are the advantages of looking at the current systems documantation?
Could save time with copies of previous analysis
Can see existing inputs, outputs and processes
Allows analyst to predict the system size required by looking at the amount of data that needs to be handled
ICT
What is this?
One-one question and answer session between system analyst and a member of staff
Analysis - researching and existing system a description of Interviews
ICT
Data validation checks
What is this?
Makes sure that data in one field is consistent with data in another field
Consistency check
ICT
Systems
Documantation and Evaluation
• Technical documentation - this is for people who may need to modify or develop the system further at a later stage
What does it contain? (7 things):
Contains: • Program flowcharts • Code listings • File / database structures • Details of validation • Error messages and meaning • Hardware and software requirements • System flowcharts
ICT
System Developmen
Describe 4 tasks that need to be done during the system development stage
I. Creating file structure to store data: • setting up tables • specifying field names • data types • field length II. Creating validation rules/checks: • in database tables for each field where it is needed III. Creating input methods: • data entry forms • creating menu systems IV. Creating output formats: • both printed and on screen
ICT
Systems
Documantation and Evaluation
What can lead to: Changes to hardware because of: • Feedback from users • Availability of new hardware • Changes within company Changes to software because of: • Feedback from users • Changes in legislation • Changes in company structure
The changes that evaluation might lead to
ICT
Investigation Methods
What are the advantages of using Observations?
Analyst can see exactly what works well and not so well
Not expensive as no one is taken away from their work
ICT
Changeover to a new system
Describe,and give advantages and disadvantages for the method of changeover called Phased
Description - When parts of the system are introduced at different times to make sure they work
Advantages - The individual parts can be fixed if any bugs occur without having to take down the entire system
Disadvantages - Can take a while as each new part has to be tested before the next can be added
ICT
Data validation checks
what is this?
Checks that the correct number of characters has been entered
Length check
ICT
Systems
Documantation and Evaluation
User information is for people who are going to use the computer system. What 7 things are contained within it?
- The purpose of the system
- How to use the system to add/delete/change data
- How to load/save/print
- What hardware is required to run the system
- Common error and what to do about them
- Tutorials
- On-line help features
ICT
What is system development?
The process of building the system
ICT
Investigation Methods
What are the disadvantages of using interviews?
Interviews take far longer than questionnaires
Expensive as interviewees need to be taken from their work
Answers may not be honest as interviewees cannot be anonymous
Interviewees might answers what they think is expected
What are these examples of? • Observation • Questionnaires • Interviews • Looking at existing paperwork
Research methods for analysis - researching an existing system
ICT - what provides this?
An overview of how a system works and helps identify
problems with the existing system
Hardware and software needed for the new system
Information requirements for the new system
What a data flow diagram provides
ICT
Data validation checks
What is this?
• When data is entered twice, and is compared before letting the user know if there are any differences. This is most commonly used when setting up an account online, to make sure you don’t accidentally press a key by mistake when entering a password
Double entry
For analysis - researching and existing system, how would you describe;
Looking at existing paperwork
Analyst looks at existing doecumentation – can see what is stored, how it is stored, presented etc.
ICT
Investigation Methods
What are these disadvantages of?
Very time consuming to look through all existing documents
Very expensive as the analyst will need to be paid
Time could be wasted if existing documentation is not relevant to the new system
Looking at the current systems documentation
ICT
Investigation Methods:
What are these advantages of?
Analyst can see exactly what works well and not so well
Not expensive as no one is taken away from their work
Using observations
ICT
Data validation checks
what is this?
Makes sure that data is in a specific format
Format check
What features should a data capture form have? (11 items)
A heading so it is clear what the form is for On screen help Clear where the answers should go Automatic validation Character boxes for names etc. (one character per box) Text boxes for answers Sufficient space for answers Drop down boxes Tick boxes for choices Clear fonts/colours Control boxes e.g. submit
ICT
Investigation Methods
What are these disadvantages of?
People often don’t complete or return them
Unclear questions can’t be explained
You may get incorrect data from misunderstood questions
It is hard to ask specific or very technical questions
Using questionnaires
ICT
Data validation checks:
Describe double entry and visual checks
- Double entry: When data is entered twice, and is compared before letting the user know if there are any differences. This is most commonly used when setting up an account online, to make sure you don’t accidentally press a key by mistake when entering a password
- Visual check: Where the person entering the data into the system carefully compares what they have entered with the original document
For analysis - researching and existing system, how would you describe observation?
Watching staff use existing system to see exactly how it works
ICT
Data validation checks
What is this?
Where the person entering the data into the system carefully compares what they have entered with the original document
A visual check
ICT
System Development
What are these and when are they used?
-Numbers from 1 to 10-
I. Normal data - data within the range which should be accepted, e.g. 5
II. Abnormal data - data outside of the range which should be rejected, e.g. 16 or sixteen
III. Extreme data - data at either end of the scale which should be accepted, e.g. 10
Three types of data that should be used when testing a new system
ICT Changeover to a new system What are these? direct parallel phased pilot
Four methods of changeover
At what stage are these things looked at?
1) How well does it meet the user requirements identified at the Analysis stage
2) How well does the system work - speed of response / quality of output
3) How easy the system is to use
4) Are there any bugs / errors in the system that need to be fixed
Evaluation stage
What are the six steps followed when a new system is being considered/ developed?
Analysis Design Development and testing Implementation Documentation Evaluation
ICT
Investigation Methods:
What are these advantages of?
Questions can be explained if misunderstood
More complex questions can be asked giving more detailed data
Questions can be changed to suit the interviewee, e.g. director compared to employee
You will get all the data as people have to answer all the questions
Using interviews
ICT
Investigation Methods
What are these disadvantages of?
They take far longer than questionnaires
Expensive as interviewees need to be taken from their work
Answers may not be honest as interviewees cannot be anonymous
Interviewees might answers what they think is expected
Using interviews
ICT
Changeover to a new system
Describe, and give advantages and disadvantages for, the method of changeover called Pilot
Description - When the new system is only used in a part of the company until it is deemed satisfactory
Advantages - Any errors can be found and fixed before fully implementing the new system
Disadvantages - Takes a while as the system has to be tested for a while, and retested if any errors/bugs are found
Explain a range check
Performed on numbers to check they are within a certain range
ICT
Changeover to a new system
What is this?
Description - When parts of the system are introduced at different times to make sure they work
Advantages - The individual parts can be fixed if any bugs occur without having to take down the entire system
Disadvantages - Can take a while as each new part has to be tested before the next can be added
The method of changeover called Phased
Explain length check
Checks that the correct number of characters has been entered
Explain limit check
Performed on numbers to make sure that data is not above or below a specific limit
What shows these? Diagrammatic representation of: Inputs Processes Outputs
Data flow diagram
ICT
What is data validation?
Validation is when a computer system checks that data entered by the user is sensible and usable
What are the advantages of using Interviews?
Questions can be explained if misunderstood
More complex questions can be asked giving more detailed data
Questions can be changed to suit the interviewee, e.g. director compared to employee
You will get all the data as people have to answer all the questions
What is double data entry?
When data is entered twice, and is compared before letting the user know if there are any differences
ICT
Investigation Methods
What are the disadvantages of using observation?
People being watched might feel uncomfortable and work differently
ICT
What are these part of:?
Analysis Design Development and testing Implementation Documentation Evaluation
The systems life cycle
ICT
Investigation Methods
What are the disadvantages of looking at the current systems documantation?
Very time consuming to look through all existing documents
Very expensive as the analyst will need to be paid
Time could be wasted if existing documentation is not relevant to the new system
ICT
Investigation Methods:
What are these advantages of?
Could save time with copies of previous analysis
Can see existing inputs, outputs and processes
Allows analyst to predict the system size required by looking at the amount of data that needs to be handled
Looking at the current systems documentation
What 2 things could evaluation lead to being changed, and what causes the changes?
Changes to hardware because of:
• Feedback from users
• Availability of new hardware
• Changes within company
Changes to software because of:
• Feedback from users
• Changes in legislation
• Changes in company structure
ICT
For analysis - researching an existing system, what are the four research methods?
Observation
Questionnaires
Interviews
Looking at existing paperwork
ICT
Systems
Documantation and Evaluation
What contains this? • Program flowcharts • Code listings • File / database structures • Details of validation • Error messages and meaning • Hardware and software requirements • System flowcharts
Technical documentation
For analysis - researching and existing system, how would you describe questionnaires?
Questionnaires are sent to staff to try to find out what they think of the current system and how they use it
ICT
What do we call the process of building the system?
system development
What does a data flow diagram provide?
Provides an overview of how a system works and help identify
problems with the existing system
Hardware and software needed for the new system
Information requirements for the new system
ICT
Changeover to a new system
list four methods of changeover
direct
parallel
phased
pilot
ICT
Investigation Methods
What are the disadvantages of using questionnaires?
People often don’t complete or return the questionnaire
Unclear questions can’t be explained
You may get incorrect data from misunderstood questions
It is hard to ask specific or very technical questions
Explain format check
Makes sure that data is in a specific format
ICT
Changeover to a new system
Describe, and give advantages and disadvantages for, the method of changeover called Parallel
Description - Running both systems simultaneously until you are certain the new one is working correctly
Advantages - The safest as you can always revert back to the old system if any bugs in the new one are found until they are fixed
Disadvantages - Most expensive as work is done twice for a period of time
Explain data type check
Checks that entered data does not contain invalid characters
For analysis - researching an existing system, how would you describe interviews?
One-one question and answer session between system analyst and a member of staff
What is this describing?
System needs to be tested to ensure that:
• It meets the clients requirements
• All bugs/errors are removed from the system
• Required output is produced
• Make sure software does not crush under certain circumstances, e.g.: when lots of people are using it
• TEST PLAN showing expected results for all possible scenarios must be produced
How the test strategy / plan should be designed
ICT
Data validation checks
what is this?
Checks that entered data does not contain invalid characters
data type check
ICT
What is this?
When a computer system checks that data entered by the user is sensible and usable
data validation
ICT
Investigation Methods
What are the advantages of using Questionnaires?
Questions can be answered quickly
Answers are more honest as anonymous
Fairly cheap
Answers can be analysed automatically using OMR
ICT
Changeover to a new system
What is this?
Description - Immediately replacing the old system with the new
Advantages - It is the most risky, but many companies use it
Disadvantages - A danger of there still being problems with the new system
The method of changeover called
Direct
What are these features of?
Paper based and electronic forms Extra for electronic forms A heading so it is clear what the form is for On screen help Clear where the answers should go Automatic validation Character boxes for names etc. (one character per box) Text boxes for answers Sufficient space for answers Drop down boxes Tick boxes for choices Radio buttons/tick boxes Clear fonts/colours Control boxes e.g. submit
A data capture form
ICT
Systems
Documantation and Evaluation
Systems need to be evaluated once it is set up and running and maintenance may need to be done
What 4 things need to be considered when evaluating a system?
- How well does it meet the user requirements identified at the Analysis stage
- How well does the system work - speed of response / quality of output
- How easy the system is to use
- Are there any bugs / errors in the system that need to be fixed
What is a visual check?
Where the person entering the data into the system carefully compares what they have entered with the original document
ICT
What is this a description of?
Watching staff use existing system to see exactly how it works
Direct observation
ICT
System Development
List the 4 tasks that need to be done during the system development stage
I. Creating file structure to store data:
II. Creating validation rules/checks
III. Creating input methods:
IV. Creating output formats:
ICT
Changeover to a new system
What is this?
Description - When the new system is only used in a part of the company until it is deemed satisfactory
Advantages - Any errors can be found and fixed before fully implementing the new system
Disadvantages - Takes a while as the system has to be tested for a while, and retested if any errors/bugs are found
The method of changeover called Pilot
Describe a consistency check
Makes sure that data in one field is consistent with data in another field
ICT
What seven things happen in analysis of a system?
Research current system and identify inputs, processes and outputs Identify problems with currenr system Identify and agree client requirements Produce cost-benefit analyisis Identify suitable hardware and software Produce a data flow diagram
A feasibility report will also be produced (is it sensible to proceed or not?)
What are these features of?
Contains information on the following:
• The purpose of the system
• How to use the system to add/delete/change data
• How to load/save/print
• What hardware is required to run the system
• Common error and what to do about them
Will also include:
• Tutorials
• On-line help features
User documentation - this is for people who are going to use the computer system
Design Stage - Systems analysis - ICT
How must screen displays/printed records be designed?
Must be designed to ensure that:
• Size of output is correct
• Full screen is used
• Colours and fonts which make the output clear
• Any descriptions/instructions are clear
What is this a description of?
Performed on numbers to check they are within a certain range
range check
ICT
Changeover to a new system
What is this?
Description - Running both systems simultaneously until you are certain the new one is working correctly
Advantages - The safest as you can always revert back to the old system if any bugs in the new one are found until they are fixed
Disadvantages - Most expensive as work is done twice for a period of time
The method of changeover called Parallel
ICT
Data validation checks
what is this?
checks data has been entered and not missed out
Presence check
ICT
Data validation checks
what is this?
Performed on numbers to make sure that data is not above or below a specific limit
Limit check
ICT
Investigation Methods
What is this?
People being watched might feel uncomfortable and work differently
the disadvantages of using observation?
ICT Investigation Methods: What is this? questions can be answered quickly Answers are more honest as anonymous Fairly cheap Answers can be analysed automatically using OMR
the advantages of using Questionnaires?
ICT
Data validation checks
explain Presence check
checks data has been entered and not missed out
ICT
System Development
describe three types of data that should be used when testing a new system?
consider ‘numbers from 1-10’
I. Normal data - data within the range which should be accepted, e.g. 5
II. Abnormal data - data outside of the range which should be rejected, e.g. 16 or sixteen
III. Extreme data - data at either end of the scale which should be accepted, e.g. 10
What are these part of? Research current system and identify inputs, processes and outputs Identify problems with currenr system Identify and agree client requirements Produce cost-benefit analyisis Identify suitable hardware and software Produce a data flow diagram
A feasibility report will also be produced (is it sensible to proceed or not?)
Analysis of a system
Design Stage - Systems analysis - ICT
How must the test strategy / plan be designed? (5 things)
System needs to be tested to ensure that:
• It meets the clients requirements
• All bugs/errors are removed from the system
• Required output is produced
• Make sure software does not crush under certain circumstances, e.g.: when lots of people are using it
• TEST PLAN showing expected results for all possible scenarios must be produced
Design Stage - Systems analysis - ICT
What is this?
Must be designed to ensure that:
• Size of output is correct
• Full screen is used
• Colours and fonts which make the output clear
• Any descriptions/instructions are clear
How must Screen displays/printed records be designed?
ICT
Changeover to a new system
Describe,and give advantages and disadvantages for the method of changeover called
Direct
Description - Immediately replacing the old system with the new
Advantages - It is the most risky, but many companies use it
Disadvantages - A danger of there still being problems with the new system
What is a data flow diagram (3 things)?
Diagrammatic representation of
Inputs
Processes
Outputs
