CHAPTER 12: SOFTWARE DEVELOPMENT

12.1 PROGRAM DEVELOPMENT LIFECYCLE 

 12.1.1 Stages 

 

 Analysis:  Understand problem, identify requirements 

 Design:  Create solution structure, algorithms 

 Coding:  Write actual program code 

 Testing:  Find and fix errors 

 Maintenance:  Update and improve after delivery 

 

 12.1.2 Development Models 

 Waterfall: 

 

 Sequential phases 

 Each phase completes before next begins 

 Good for well-defined requirements 

 

 Iterative: 

 

 Develop in cycles 

 Each iteration produces working version 

 Allows feedback and improvement 

 

 RAD (Rapid Application Development): 

 

 Quick development using pre-built components 

 Emphasis on prototyping 

 Fast user feedback 

 

 12.2 PROGRAM DESIGN 

 12.2.1 Structure Chart 

 Purpose: Decompose problem into sub-tasks 

 Shows: 

 

 Modules/procedures/functions 

 Parameters passed between modules 

 

 12.2.2 State-Transition Diagrams 

 Purpose: Document algorithm behavior 

 Shows: 

 

 Different states 

 Transitions between states 

 

 12.3 PROGRAM TESTING AND MAINTENANCE 

 12.3.1 Error Types 

 

 

 

 

 Type 

 Description 

 

 

 

 

 Syntax 

 Violation of language rules 

 

 

 Logic 

 Incorrect algorithm implementation 

 

 

 Runtime 

 Error during execution 

 

 

 

 

 

 12.3.2 Testing Methods 

 

 

 

 

 Method 

 Description 

 

 

 

 

 Dry Run 

 Manual execution using test data 

 

 

 Walkthrough 

 Team reviews code 

 

 

 White Box 

 Tests internal structure 

 

 

 Black Box 

 Tests functionality only 

 

 

 Integration 

 Test combined components 

 

 

 Alpha 

 Testing by developers 

 

 

 Beta 

 Testing by users 

 

 

 Acceptance 

 Final testing by client 

 

 

 

 

 

 12.3.3 Test Data 

 

 

 

 

 Type 

 Description 

 

 

 

 

 Normal 

 Typical valid data 

 

 

 Extreme/Boundary 

 At limits of valid range 

 

 

 Abnormal/Invalid 

 Invalid data 

 

 

 

 

 

 12.3.4 Maintenance Types 

 

 

 

 

 Type 

 Description 

 

 

 

 

 Corrective 

 Fixing errors 

 

 

 Adaptive 

 Adapting to environment changes 

 

 

 Perfective 

 Improving performance/functionality