Contents:
Creating a new information system
The system life cycle
Analysis stage
Design stage
Implementation stage
Testing stage
Documentation stage
Evaluation stage
System Analysis Test

System Analysis And Design

Creating a new information system

In Oakley College have a problem with there libary, some of there books have gone missing. You have been assignated create a system to try and solve this problem.What you have to do:

Ask head teacher what they want (how can we do this?).

Design the new system (on paper draw a plan of what we are going to do and how it will work).

Build a prototype of the new system and test it (probably do it at the office).(Why do we do this?).

Implement the system (we can build the system properly and then install it at the school).



Write some user documentation(some guides) on how to use it and some for the IT technician so he knows how to fix it if it breaks. (who would the guides be for?)

Each year will we come to the school and evalute the system and see how it is working and when it is no longer sufficient we will start the process again.

The process of creating /altering systems:
1.Analysis.
2. Design.
3. Implementation.
4. Test.
5. Documentation.
6. Evalvation.


See images.
10/10 Excellent

The system life Cycle:

240px-SDLC-Maintenance-Highlighted.png
This is not your own diagram… it’s missing a stage!!

8/10

Organisation need to develop a new information system. This is the reasons:


  • They want it computerize because they where previously manually.
  • The existing computer system is too small to carry out.
  • Is outdated and no longer suited to the origination’s needs.
  • The existing system has to be replaced.

In this section is important because is one of your main portfolio tasks is to design and produce a working system.

There are stages to create a information system. All together are called the system life cycle. Move the organisation through the systems life cycle are called systems analysts.


The stages of the systems life cycle:

Identify user requierements


The first stage of the process is to identify user requierements. In other words, find out from them the tasks that they need the system to perform and the way in which they would like the system to perform them. The main aim of the systems analyst is to produce a computer system which eets these needs.

Produce a design specification

At this stage the systems analyst specifies the hardware and software that will make up the system, together with how the system will enable data to be input, processed and output to the end user. The design will also explain how the systems analyst will test the system and the data that it will use to make sure that the system works properly.

Test the system

At this stage the systems analyst will need to build a first version of the system. This working model will then need to be tested to make sure that the full system will work properly. The system will need to have data input into it in order to see whether it processes in the ways that were designed.

Implement the system

This stage is often called the implementation stage. In this part of the process the final syste is built and installed.

Produce user documentation

This stage can happen at the same time as the system is being implemented. It certainly needs to happen before the users are introduced to the system. The systems analyst will not be available to every user of the system. Therefore a range of guides need to be written that fully explain how the system works and how it can be maintained.

Evalute the system

This stage brings the process to a close but also allows the cycle to begin again. Once the system is in use it needs to be constantly monitored to see how well it eets the aims originally set for it at the start of the cycle. There may come a time when the system no longer eets the aims set for it and so a new system needs to be developed. The systems life cycle starts all over again.
Good!

Analysis Stage

1. What are the inputs and outputs of the current and proponed system?
Inputs are the information you put in the system. Outputs are the print out papers.

2. How does the current system work?

Manually.

3. What are the problems with the current system?
Manually, Small capacity to carry out work, outdated, no longer to the organasition's needs, needs to be replaced.


4. What hardware and software are needed for the proposed system?
Hardware and software that make the system and enable inputs and outputs.

5. What are the user requirements for the new system?

That they need the system to perform and the way in which they would like the system to perform them. The main aim of the systems analyst is to produce a coputer system which meets these needs.
10/10
Design Stage

In the design stage you need to design:


  1. The process (flow diagrams to show how the system works).
i.e Students choose books = card presented…
2. What hardware and software are needed to complete the process.
i.e. Bar code reader, database…
3. Data capture forms = inputs into the system.

4. Reports = outputs out the system.

5. File structures.
File is an electronic version of a document.

10/10

Validation:

Form of making sure data going into the database is consistent, valid, correct...
Ways or Techniques of Validation:
- Existence: is the data exist. i.e
- Length: is if it is the right lenght. i.e A telephone has to have 9 digits.
- Invalid character: is is the correct information.
- Format: is how the informaton is put in. It's has to be the same standard. i.e. Date = 12/03/2000 is the standard and people do it by put in 03/12/2000.
- Presence: is If the information is put in the correct way. i.e Las Palmas not =Las Palma.
- Check digit: is is to check if all digits are correct.

The School wants to update stock control system for the school uniforms.
Design a Solution

Should include:

  • A list of Inputs / Outputs.
  • Suggested Hardware and Software.
  • Data flow diagrams detailing the processes involved.
  • Data input forms.

Implementation Stage

The school wants to update their stock control system for the school uniforms.

Solution !

Form:


Customer:
Items:
Size:
Quantity:
Date:

Input:
*customer information
*stock

Output:
*receipt

Hardware
*Computer
*Web server
*Scanner

Software
*database holding the stock and customers.


Marshall’s Bakery makes bread and cakes for use in hotels and restaurants. In April 2001 it introduced a new computer system. The old system was shut down at 6:00pm on Friday. Staff was paid overtime to come into work on the Sunday to practice using the new system. On the Monday morning the new system crashed. Staff had to revert to using the old system until the problem was fixed.

Which implementation method was used in Marshall’s Bakery?

v Direct Implementation.
Explain how a different method of implementation might have prevented this problem from happening.

v Parallel Implementation because the benefits that will let parts of the system can be tested in the real environment without harming the operations of the Organisation.

Implementation:
In this stage the developed system and or database are installed in the production environment. The implementation stage builds in the results of the other stages (Analysis, Design…) this stage implements the components of the system constructive and or required the development stage.
The implementation includes:

v Direct Implementation - You shut down the old one and have straight the new one.
v Parallel Implementation – You use the two at the same time.
v Phased Implementation – You use different parts of the system and tested while you are using the old one.

Alcampo is using a self checkout (parallel implementation) because if they used direct and the system crashed the would have to shut the Alcampo until it was fixed and Phased too much time spend they tried to use parrallel so if the new crashes the old is until working.
Good 10/10

Testing Stage

To prove that something is working correctly.
Notes: once the model has been implemented it needs
to be tested. First a test plan is drawn up. What is a test plan?
A test plan is a scheme for testing a program (or system) giving details of the tests and the data that is to be used.
The model can be tested with different types of data.

There is no substitute for the use of live data to test a system, explain why.
Because is use data that people are using for the test.
Software needs to be tested to make sure that it works correctly. Whole new computer systems also need to be tested.
A test plan is devised giving details of all tests to be carried and the data that is to be used.
The test data must include normal data, null data, invalid data and extreme data.





The model can be tested with different types of data. Name the different types of data and give an example


There is no substitute for the use of live data to test a system, explain why.
Software needs to be tested to make sure that it works correctly. Whole new computer systems also need to be tested.
A test plan is devised giving details of all tests to be carried and the data that is to be used.
The test data must include normal data, null data, invalid data and extreme data.


Testing:
- Library checkout.
- Objectives: Make sure says works correctly.


Test
Values
Expected Result
Actual Result
1) Random scans of books (real data)
Book 1
Book 2…

Check books.

2) Member’s cards.
Personal card.
Member’s information.

3) New member card.
Members information into database.
Members information in card.

4) New books scans
Books information.
Books information on database.

Isn't this missing other types of tests? Like books that don't belong to the library, many of the same book... 8/10
Documentation Stage:


Documentation is instructions for end users explaining how system works (how to operate).

1) What 3 types of documentation are needed for a new system?
v Installation Documentation, User Documentation and Maintenance Documentation.

2) What is contained in each piece of documentation?
v Installation documentation will contain information that will help the engineer to install the system.
v User documentation this will enable ordinary users of the computer system to carry out operations and commands using the system.
v Maintenance documentation this will enable ICT systems managers and technicians to carry out tasks such as system back-up, fault finding and repair, as well as upgrades to the system itself.

Evaluation Stage:

Evaluating is a much broader task than monitoring, as it involves judging the extent to which the system is able to meet the objectives set for it.

1) Why do we need to evaluate a system?
v Because maybe the system dosen't have of the objectives the people or user wants overtime...
Good 10/10

System Analysis Test


Systems Analysis Assessment


1. The owner of several mobile phone shops wants to
computerise the records of the stock and customers. The systems analyst will need to find out how the existing systems work. She will need to find out how records of phones and customers are kept at the moment.

a) There are four ways she could find out this information. Describe in detail two of these ways.
Questionnaires/Interviews: To find out specific information.
Observing a user: To absorb how they use the system and what errors they commit.
[4]

b) In the analysis stage, in addition to finding out how the current system works, what will the system analyst need to find out? Name two things.
He would need to find out, how they would like the future system to be like, and a table with the positive and negative of the current system. [2]

c) After analysing the existing system the systems analyst will design a database
Consisting of the customer file and the stock file. Apart from the structure of these files, describe four items that the systems analyst will need to design for the database.
Inputs + Outputs, Suggested Hardware and Software, Data flow diagrams detailing the processes involved, Data input forms.

[4]

2. Pupils in a school are sitting an exam paper in IT. The IT teacher wishes to keep the results in a spreadsheet using the column headings shown below. The exam will be marked out of 60 and the pupils’ scores will be typed into the Exam Score column.


A
B
C
D
E
1
Name
Form
Gender
Exam Score
Pass/Fail
2





3






(a) The teacher wants to use a validation check which only allows numbers between 0 and 60 to be typed in. What is the name of this type of validation check?

Range Check.
[1]
(b) She types in the following exam scores to test that the validation works: 0, 45, 60 and 87.Using the data above write down one example of:
(i) Normal data: 45.
(ii) Extreme data: 60 or 0.
(iii) Abnormal data: 87.
[3]


3. Noreen Patel owns several book shops around the country. She wants to keep details of each book on a computer database. All the details of each book will be typed into a screen input form.
a) Design a screen input form which could be used for typing in one book’s details. – Use about half a page.




Title: How many copies:
Author: Location:
Collection: Yes No
Number:
Type (non-fiction, romantic):
Company:
Nª Company:




[5]

d) For two of the fields explain specifically what validation check will be used?
For the number of the book I or you would need to use the check digit and for the name and author of the book I or you would need to use the existence.
[4]
4) When a system is designed documentation needs to be produced to help users use the system. What three types of documentation are produced and name two things that are contained in each.
Installation Documentation will contain information that will help the engineer to install the system. User Documentation this will enable ordinary users of the computer system to carry out operations and commands using the system. Maintenance Documentation this will enable ICT systems managers and technicians to carry out tasks such as system back – ups, fault finding and repair, as well as upgrades to the system itself.

[9]

e) After a system is implemented, it is evaluated. Give two reasons why a system should be evaluated.
To see if after a period of time the system continues having all the customers’ specification. If could be better done. [2]

5) A school wants to design a new system to monitor the books in the library. The requirements they have are:

  • The system must be easy to use for both the teachers and pupils
  • The system must record which books are taken out of the library and must show which students have the books.
  • The school would like each student to have their own library card with a magnetic stripe or chip.
  • The school would like each book to be catalogued using the barcode.

Design

  1. A flow chart showing the total process from when the student chooses the book to when the book is returned – include ALL stages including any processing the computer needs to do.

Student chooseCard PresentedCard Checked


Card given back ← Record the book and ← System checks if the student
the date on the card hasn´t got any overdue books




Student receives card and book → Student goes out of the libary → Student reads book





[8
  1. A test plan. Include 4 items that would need to be tested and write down the expected results.

Test
Values
Expected Result
Actual Result
1) Random scans of books (real data)
Book 1
Book 2…

Check books.

2) Member’s cards.
Personal card.
Member’s information.

3) New member card.
Member’s information into database.
Member’s information in card.

4) New books scans
Books information.
Books information on database.


[8]





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