Software Design and Development - Analysis and Design Flashcards
What happens in the analysis stage?
A systems analyst creates a software specification. The specification includes the purpose and functional requirements (inputs, processes, outputs)
What is meant by the purpose of software?
The purpose of software is usually defined in a few short paragraphs, providing a written statement of what the software should do
What are the functional requirements of a program?
The functional requirements of a program are defined as inputs, processes and outputs. A list of inputs that will come from the user, a sensor or a file are included. The processes focus on tasks the program will need to perform, such as validating input, or calculating an average. The outputs are a list of what the program will output, usually on screen but possibly to a file.
What are the three best methods used for designing programs?
When designing a program, it is possible to use:
Pseudocode
Structure Diagrams
Flowcharts
In a structure diagram what does a process symbol look like
A process is shown as a rectangle, with text
added to the middle to describe the process
In a structure diagram how is a loop represented?
A loop is shown as an oval, with text added to the middle to describe the loop
In a structure diagram how is a decision (IF) represented?
Selection statements are used when decisions need to be made, usually to represent the need for an IF statement or the clause on a conditional loop. A diamond shape with text in the middle is used.
In a structure diagram how is a pre-defined function represented?
A rectangle with an extra line down the left and right sides. Pre-defined functions can be used to return single values. The three in the course are random, round and length
What is pseudocode?
Pseudocode is a written list of steps used to design a program. Main steps are listed e.g. 1, 2, 3. Each main step is then refined e.g. 1.1, 1.2, 1.3, 1.4 etc.
One line of pseudocode usually results in one line of code when implementing (creating the program).
In flowcharts how is the flow shown?
A straight line with an arrow. The flow line symbol is used to show the sequence of instructions .
What symbol is used to represent the start and end of a flowchart?
The terminal symbol is used to mark the start and end of the flowchart. It is a rounded rectangle with the word start or end in it.
What symbol is used to represent initiailisation in a flowchart?
A hexagon shape is used. Shows declaration of variables (including arrays) or initialisation (setting an initial value)
What symbol is used to show input or putput in a flowchart?
A diamond shape is used. Shows that data will come into the program (input) or be sent out from the program (output)
What symbol is used to show a decision in a flowchart?
A diamond shape is used. Used to show selection statements e.g. an IF statement or the clause on a conditional loop
What symbol is used to show a process in a flowchart?
A process is shown as a rectangle, with text added to the middle to describe the process
