1. Software Development Approaches
Structured Approach

2. Formal Stages of the Structured Approach
Define the problem
Plan the solution
Build the solution
Check the solution
Modify the solution

3. Software Life Cycle Define the problem Modify the solution Plan the
Build the
solution
Check the
solution 3
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4. Waterfall Model Define the problem Plan the solution Build the
Check the
Modify the
Define the
problem
Each stage “flows” on to the next stage

5. Defining the Problem Systems analyst and management
The problem must be fully understood before a solution can be developed
Identification of inputs, outputs and processes
A requirements definition is developed

6. Planning the Solution (1)
Identification of a suitable development approach
Design of appropriate algorithms
Modularisation
Determination of appropriate data structures
Design of test data and expected output

7. Planning the Solution (2)
Desk check of the algorithms
Identification of existing code that can be used

8. Building the Solution
Coding of the solution in an appropriate language
Testing of the solution using test data
Documentation of the solution, including
Algorithms
Tutorials
Test data and expected output
Data dictionary

9. Checking the Solution Testing the completed solution using test data
Testing performance under real conditions
Users test the solution & identify problems
Evaluation of the completed solution
Compared with the original requirements definition

10. Modifying the Solution
All software products have a life span. They need to be upgraded to:
Include new functionality
Improve existing functionality
Maintenance programmers perform upgrades
Changes must be fully documented