INFS 6225 ObjectOriented Systems Analysis Design Chapter 7

INFS 6225 Object-Oriented Systems Analysis & Design Chapter 7: Moving on to Design

System Design § § § Decisions about how to build a system Create a blueprint for the “To Be” system HW, SW, & Architecture decisions are made § User Interface & system input/output decisions are made

Evolving Analysis Models into Design Models § Factoring – creating a superior (parent) class so that attributes may be shared & reused § Refinement – creating subclasses (child classes) to share attributes § Partitioning – decomposing a larger system into subset systems

Layers § Layer – element of the software architecture of the evolving system (5 layers): 1. Foundation – outlines classes that comprise system 2. System Architecture – communication among system components 3. Human-Computer Interaction – how users interact with system 4. Data Management – how classes are stored, related, & retrieved 5. Problem Domain – how classes meet business problem & system specifications

Question § What layers could be identified in a bank ATM (Automated Teller Machine) System?

Package § Package – Group of Classes § Package Diagram – Diagram of only Packages § Can used to group Classes together by Layer

Design Strategies § Three Strategies: 1. Custom Development 2. Packaged Software 3. Outsourcing § Question – What are the pros/cons of each? (chart in Chapter 8)