Coupling in Software Engineering

Data coupling problems

• Too many parameters - makes the interface difficult to understand and possible error to occur
   
• Tramp data - data ‘traveling’ across modules before being used

Stamp coupling

• A composite data is passed between modules
   
• Internal structure contains data not used
   
• Bundling - grouping of unrelated data into an artificial structure

Control coupling

• A module controls the logic of another module through the parameter
   
• Controlling module needs to know how the other module works - not flexible!

Hybrid coupling

• A subset of data used as control
   
• Example: account numbers 00001 to 99999
  ​
• If 90000 - 90999, send mail to area code of last 3 digit (000 - 999)

Common coupling

• Use of global data as communication between modules
   
• Dangers of
• ripple effect
   
• inflexibility
   
• difficult to understand the use of data

Content coupling

• A module refers to the inside of another module
   
• Branch into another module
   
• Refers to data within another module
   
• Changes the internal workings of another module
   
• Mostly by low-level languages