Errors found at integration are costly to fix - “Integration is the most costly phase” Requires the most people and equipment - “Integration is the most repeated phase” Required after major upgrades Tools that reduce integration time also reduce cost

From the Script: SLIDE 34 - Program Integration

As this study conducted by CelsiusTech of Sweden shows again, errors detected and corrected later in the software development lifecycle are more costly to correct. They found that the integration phase was the most costly, requiring more people and equipment than the other phases. Further integration is the most repeated phase. It is required after all major upgrades.

Due to the strong typing and modularity of the Ada language, integration is probably the phase in which Ada's advantages are most clearly visible. The fact that integration makes such a large contribution to total cost, is a main reason for Ada's competitive lifecycle cost advantage.