Program Development Life Cycle (Cambridge International IGCSE Computer Science)

Analysis

Spec point — "1 Understand the program development life cycle, limited to: analysis, design, coding and testing"

Analysis

What is the analysis stage of the program development life cycle?

• The analysis stage of the program development life cycle is to precisely understand the problem the program is intended to solve

What role does abstraction play in the analysis?

• Abstraction is the act of removing unimportant details from the problem to focus on important elements such as:

  • Core functionality
  • Requirements

• An example of abstraction would be the London underground train route map; travellers do not need to know the geographical layout of the routes, only that getting on at stop A will eventually transport you to stop B

Core functionality

• Using abstraction helps to identify the fundamental components of what the program is going to solve
• Before tackling a problem, it needs to be clearly understood by everyone working on it
• The overall goal of the solution needs to be agreed as well as any constraints such as limited resources or requiring a platform specific solution

Requirements

• To create a solution, a requirements document is created to define the problem and break it down into clear, manageable, understandable parts by using abstraction and decomposition
• A requirements document labels each requirement, gives it a description as well as success criteria which state how we know when the requirement has been achieved

Design

Spec point — "1 Understand the program development life cycle, limited to: analysis, design, coding and testing"

Design

What is the design stage of the program development life cycle?

• The design stage of the program development life cycle involves using techniques to come up with a blueprint for a solution

• Ways the design of a solution to a problem can be presented include:

  • Structure diagrams
  • Flowchart
  • Pseudocode

Coding

Spec point — "1 Understand the program development life cycle, limited to: analysis, design, coding and testing"

Coding

What is the coding stage of the program development life cycle?

• Developers begin programming modules in a suitable programming language that works together to provide an overall solution to the problem

• As each developer programs, they perform iterative testing

  • Iterative testing is where each module is tested and debugged thoroughly to make sure it interacts correctly with other modules and accepts data without crashing or causing any errors

• Developers may need to retest modules as new modules are created and changed to make sure they continue to interact correctly and do not cause errors

Testing

Spec point — "1 Understand the program development life cycle, limited to: analysis, design, coding and testing"

Testing

What is the testing stage of the program development life cycle?

• Once the overall program or set of programs is created, they are run many times using varying sets of test data
• This ensures the program or programs work as intended as outlined in the initial requirements specification and design and rejects any invalid data that is input
• Examples of test data include alphanumeric sequences to test password validation routines