Design Principles Modularity ◆Abstraction Focus only on relevant properties ◆Decomposition -Divide software into separately named and addressable modules ◆Encapsulation Group related things together. ◆Information Hiding Hide implementation details from the outside Separation of Concerns Ensure that each module only deals with one concern ·Low Coupling aim for low coupling among the modules High Cohesion aim for high cohesion within one module Object Oriented Analysis and Design 3Object Oriented Analysis and Design 3 Design Principles  Modularity w Abstraction § Focus only on relevant properties w Decomposition § Divide software into separately named and addressable modules w Encapsulation § Group related things together. w Information Hiding § Hide implementation details from the outside w Separation of Concerns § Ensure that each module only deals with one concern § Low Coupling • aim for low coupling among the modules § High Cohesion • aim for high cohesion within one module