What are the different types of Integration Testing?

Big Bang Integration Testing:

• All modules integrated simultaneously and tested as complete system
• Quick to implement but difficult to isolate defects
• Best for small systems with few integration points

Incremental Integration Testing:

• Modules integrated and tested one by one
• Better fault localization and easier debugging
• Requires more planning but provides better control

Top-Down Integration:

• Starts from top-level modules, progressively integrates lower levels
• Uses stubs to simulate lower-level modules not yet integrated
• Good for systems with well-defined hierarchical structure

Bottom-Up Integration:

• Starts from lowest-level modules, progressively builds upward
• Uses drivers to simulate higher-level modules
• Effective when lower-level modules are stable and reliable

Sandwich/Hybrid Integration:

• Combines top-down and bottom-up approaches
• Tests critical paths from both directions simultaneously
• Balances benefits of both approaches