03 analysis of_requirementsspecification

1. ANALYSIS
Requirements
Specification
Software
Development

2. Software Development Lifecycle
This is used by software designers - the whole
design process can be thought of as a cycle
The stages are:
Identify - Define requirements and specification
Design - Plan the solution to the problem
Develop - Produce the program code
Test - Locate and remove any errors
Evaluate - Review against program requirements

3. Requirements Specification
3
The first stage of the design process is based upon analysing
the user’s requirements to determine what is achievable with
the resources available
Prioritise the most important features and decide what will
be included in the first version of the software and what can
be left out and put on the ‘wish list’ for future versions.
Identifies WHAT the program must be able to do
Including Inputs, Outputs and Processing required
You also need to consider resource limitations (called
constraints) which typically involve time and money.
Then write a formal specification for the program

4. Documentation
Requirement Specification:
Inputs are required from the user
Outputs expected by the user
Processing needed to provide functionality
Hardware devices and min spec
Software required, language depends on hardware, OS
Constraints e.g. Development Schedule, Costs
Screen Designs
Shows how the program will work

5. Requirements Specification
Inputs: List of all the data that is input by the user
Give specific details of the actual data, e.g. first name and
last name of user
Identify valid and invalid values for text and acceptable
ranges for numeric data
Outputs: List of all output expected by the user
Give specific details of the actual data and format, e.g.
Monthly sales report which will be displayed in a bar
chart, showing total sales for each product
Include any help information e.g. Instructions, error
messages or visual feedback

6. Requirements Specification
Processing: Give details of all the functions the program
will need to have.
You should break this down into each processing task e.g.
validation, calculations, formatting etc.
Explain what each function should do (not how – yet!)
There could be many of these in your proposed system
Constraints: Identify any resource limitations
It could include budget, development timescales, hardware
devices, training requirements, special needs of users etc.
Give specific details of schedule inc. dates for prototype
(design), develop and test
Break down costs into hardware and development hours
• e.g. 10 PCs @ £500 = £5,000

7. Screen Designs
If it has a front interface, provide a
storyboard to show screens at various
stages of the program
Create them…
On paper, Word or Visio…
In Visual Studio…
They must show
The prompts the user will see
Example input
Example output