Coupling Categories

Common

¨      Module m1 and m2 are common coupled if m1 and m2 access a global data structure (write/read).  They are not common coupled, if action to the data set is read/read or write/write

¨      Advantages

·        Performance.  There is no overhead in parameter passing.

¨      Consequences

·        A modification of the global data structure may impact every common coupled module.

·        If a module references a common environment, it is difficult to use that module elsewhere.