Identifying Functional Requirements (SQA National 5 Computing Science): Revision Note

The analysis phase

• In Software Design and Development (SDD), the analysis phase identifies what a program must do

• This involves defining the functional requirements of the problem

• Functional requirements describe the inputs, processes, and outputs needed to solve the problem

Inputs

What is an input?

• An input is data or information the program receives before it is processed

• Inputs can come from a variety of sources, such as:

  • Users – keyboard, mouse, controller, microphone

  • Sensors – temperature, pressure, movement

Processes

What is a process?

• A process is an action or calculation that transforms inputs into outputs

• The CPU executes the instructions that define the process

• Common examples include:

  • Comparing two numbers

  • Calculating an average

  • Sorting or searching data

Outputs

What is an output?

• An output is the result of the processing in a program

• Outputs show whether the program works as intended

• Outputs can include:

  • Numbers – results of calculations

  • Text – displayed messages or information

  • Images or sounds – visual or audio feedback

  • Actions – triggering another event or process

Example 1 - Area of a shape

• A user wants to write a program to calculate the area of a shape

Example 2 - Average test score

• A teacher wants to calculate the average mark achieved on a test amongst students in a class

• The teacher needs to enter how many students in the class and for each students a score out of 50