1. ICS 3UI - Introduction to Computer Science
ICS 3MI - Computer and Information Science
ICS 3MI - Computer and Information Science
ICS 3UI - Introduction to Computer Science
The Software Development Life Cycle (SDLC)
Also known as the Classic Life Cycle Model or the Linear Sequential Model (or) the
Waterfall Model.
What is SDLC?
The software development life cycle is the entire process of formal, logical steps
taken to develop a software product.
This step-by-step process enables programmers to use their time more efficiently
and helps to design error-free logic for their programs.
This model is based on the following:
Analysis/Requirements
Design
Code
Test and debug
Maintenance

2. ICS 3UI - Introduction to Computer Science
ICS 3MI - Computer and Information Science
ICS 3MI - Computer and Information Science
ICS 3UI - Introduction to Computer Science
The Software Development Life Cycle (SDLC)
1. Analysis/Requirements
Define the problem using the three step problem-solving approach or the
six step problem-solving model. You must have a clear idea of what data
(or input) are given and the relationship between the input and the desired
output.
2. Design
Plan the solution to the problem. Find a logical sequence of precise steps
that solve the problem. Such a sequence of steps is called an algorithm.
Every detail, including obvious steps, should appear in the algorithm. Flowcharts,
pseudo code and top-down charts are three methods that are used to help break a
problem into a sequence of small tasks the computer can perform to solve the
problem. Sample data should also be used to test the logic of the algorithm by
hand to help ensure that it is correct.

3. ICS 3UI - Introduction to Computer Science
ICS 3MI - Computer and Information Science
ICS 3MI - Computer and Information Science
ICS 3UI - Introduction to Computer Science
The Software Development Life Cycle (SDLC)
3. Code - Translate the algorithm into a programming language.
4. Test and debug
Locate and remove any errors in the program. Testing is the process of
finding errors in the program, both coding errors and logic errors.
Debugging is the process of correcting errors that are found.
5. Maintenance
Documentation is intended to allow another person, or the programmer at
a later date, to understand the program. Documentation can be either
internal or external. Internal documentation consists of statements within
the code of the program that are not executed but are there to explain what
the code is designed to do. External documentation can consist of online
instructions to the user such as a detailed description of what the program
does and how to use the program. It could also be offline instructions such as
a user manual.

4. ICS 3UI - Introduction to Computer Science
ICS 3MI - Computer and Information Science
ICS 3MI - Computer and Information Science
ICS 3UI - Introduction to Computer Science
The Software Development Life Cycle (SDLC)
This is known as the waterfall model of software development.

5. ICS 3UI - Introduction to Computer Science
ICS 3MI - Computer and Information Science
ICS 3MI - Computer and Information Science
ICS 3UI - Introduction to Computer Science
The Software Development Life Cycle (SDLC)
There is a certain amount of backtracking in the actual evolution of a
piece of software of any complexity, particularly if the software is
constantly being updated. The Iterative Model reflects this.

6. ICS 3UI - Introduction to Computer Science
ICS 3MI - Computer and Information Science
ICS 3MI - Computer and Information Science
ICS 3UI - Introduction to Computer Science
The Software Development Life Cycle (SDLC)
After testing, usually (i.e. almost always) some problems are found that
must be analyzed again and then they must be made to conform to the
required specifications, which in turn may require design changes and
then must be re-implemented (coded). This process must be continuously
repeated until the product can be released (i.e. it is perfect).

7. ICS 3UI - Introduction to Computer Science
ICS 3MI - Computer and Information Science
ICS 3MI - Computer and Information Science
ICS 3UI - Introduction to Computer Science
The Software Development Life Cycle (SDLC)
Questions or Comments?

8. ICS 3UI - Introduction to Computer Science
ICS 3MI - Computer and Information Science
ICS 3MI - Computer and Information Science
ICS 3UI - Introduction to Computer Science
The Software Development Life Cycle (SDLC)