上大名.2 Why is Design so Difficult? SHANGHAI JIAO TONG UNIVERSITY Analysis:Focuses on the application domain Design:Focuses on the solution domain Design knowledge is a moving target The reasons for design decisions are changing very rapidly Halftime knowledge in software engineering:About 3-5 years What I teach today will be out of date in 3 years Cost of hardware rapidly sinking “Design window": Time in which design decisions have to be made Technique Time-boxed prototyping Software EngineeringSoftware Engineering 1.2 Why is Design so Difficult? Analysis: Focuses on the application domain Design: Focuses on the solution domain • Design knowledge is a moving target • The reasons for design decisions are changing very rapidly • Halftime knowledge in software engineering: About 3-5 years • What I teach today will be out of date in 3 years • Cost of hardware rapidly sinking “Design window”: • Time in which design decisions have to be made Technique • Time-boxed prototyping