Matching and mismatching of system elements

This is a fascinating pattern, which needs to be understood well before it is 

As an engineering system evolves, its individual subsystems are initially unmatched, then matched, then mismatched, and finally a dynamic process of matching-mismatching emerges. 

Let us explain first several terms used in this pattern. 

Unmatched systems are two or more entirely incompatible systems put together, for example a diesel fuel system installed in a car with a gasoline internal combustion engine. 

Matched systems are two or more compatible systems working together, which were optimized as subsystems of the system they create together, for example, carefully optimized integrated braking and suspension systems in a racing car. 

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