Layered vs Big Ball of Mud

Layered arch vs Big Ball Of Mud: 

§  Separation of concerns -  Each layer encapsulates distinct functions –eg Presentation , Business Logic, Data Access in traditional three-tiered architecture.

§  If multiple presentation technology needs to be supported – say Mobile and Web based views, only the presentation tier is affected

§  If a different kind of data access pattern needs to be supported – say Memcache based caching, only the data tier is affected

§  Allows Reuse – lower layers can be re-used by the layers above it.

§  Testability – Each layer can be tested independently.

§  Maintainable – if view breaks, look in the presentation tier. If data seems wrong, look in the data access tier, if business logic seems wrong, look at the business tier

§  Fosters Developer specialization – UI developers looking at Presentation layer