SOA& Web Service 教育部-BM专业综合改革项目 Why are interfaces so expensive to build and maintain? Application interface logic is intertwined with business logic Tightly integrated interfaces are difficult to change. The more interfaces, the more complex the application -interface logic may exceed business logic. In such circumstances, reuse becomes difficultand im practical. Lan Zhou UniversitySOA & Web Service Lan Zhou University 教育部-IBM专业综合改革项目 Why are interfaces so expensive to build and maintain? ▪ Application interface logic is intertwined with business logic. ▪ Tightly integrated interfaces are difficult to change. ▪ The more interfaces, the more complex the application — interface logic may exceed business logic. ▪ In such circumstances, reuse becomes difficult and impractical