上游充通大￥ SHANGHAI JIAO TONG UNIVERSITY 2.1 Reality and Model Reality R: Real Things,People,Processes happening during some time,Relationship between things Model M:Abstractions from (really existing or only thought of things,people processes and relationships between these abstractions. Software EngineeringSoftware Engineering 2.1 Reality and Model Reality R: Real Things, People, Processes happening during some time, Relationship between things Model M: Abstractions from (really existing or only thought of ) things, people , processes and relationships between these abstractions