Software Development Tasks Place Order Problem Inventory Shipping Space Descriptions of problem Business Process (Human:Requirements) Natural Language A Gap between two Spaces Descriptions of solution Programming Language (Human:Designing Program Execution of program 建造 Solution Computer System SpaceSoftware Development Tasks Problem Space Business Process Place Order Inventory Shipping Computer System Descriptions of problem (Human: Requirements) Natural Language Descriptions of solution (Human: Designing Program ) Programming Language Solution Space Execution of program A Gap between two Spaces