Practical Notes 2023-2025
, to verify the overall functionality and performance of the program
1. Algorithm Design & Problem- by evaluating its behavior with a variety of inputs.
Solving
1.2. Structure Diagrams
1.1. Program Development Life Cycle (PDLC) Every computer system is made up of sub-systems, which are in
Analysis turn made up of further sub-systems. Structure Diagrams – The
Design breaking down of a computer system into sub-systems, then
Coding breaking each sub-system into smaller sub-systems, until each
Testing one only performs a single action. A structure diagram
Maintenance diagrammatically represents top-down design. Example below.
Analysis
Before solving a problem, it is essential to de ne and
document the problem clearly, known as the "requirements speci
cation" for the program. The analysis stage involves using
tools like abstraction and decomposition to identify the speci c
requirements for the program.
Abstraction focuses on the essential elements needed for the 1.3. Pseudocode & Flowcharts
solution while eliminating unnecessary details and information.
Pseudocode - Verbal representation of an algorithm (a process
Decomposition involves breaking down complex problems into or set of steps) and owcharts are a diagrammatic
smaller, more manageable parts that can be solved individually. representation.
Daily tasks can be decomposed into their constituent parts for Flowcharts: A owchart shows diagrammatically the steps required
easier understanding and solving. to complete a task and the order that they are to be performed
Algorithm: These steps, together with the order, are called an
Design algorithm
The program speci cation derived from the analysis stage is used
as a guide for program development. During the design stage, the
programmer should have a clear understanding of the tasks to be
completed, the methods for performing each task, and how the
tasks will work together.
Documentation methods such as structure charts, owcharts,
and pseudocode can be used to formally document the
design of the program.
Coding and iterative testing
The program or set of programs is developed based on the design.
Each module of the program is written using a suitable
programming language.
Testing is conducted to ensure that each module functions
correctly.
Iterative testing is performed, which involves conducting modular
tests, making code amendments if necessary, and repeating tests
until the module meets the required functionality.
Testing
The completed program or set of programs is executed multiple
times using various sets of test data. This testing process
ensures that all the tasks within the program work together as
speci ed in the program design.
By running the program with di erent test data, potential issues
and errors can be identi ed and addressed. The testing phase aims
, Array: Array is similar to variable but it can store multiple values of