CIS 3250 Lecture 27: 27 Design Decisions and Construction
27 Nov 2017
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Document Summary
What are requirements: a statement about what an intended product should do or how it should perform. Use requirements checklist at the end of the section to assess the quality of your requirements. Make sure everyone knows the cost of requirements changes. Use development approaches that accommodate changes (consider) dumping the project. Keep your eye on the business case for the project. Two main approaches to system design: top-down design, aka decomposition. Top-down pros: easy to understand and use, programmers are generally good at breaking problems into pieces, construction details are hidden in lower levels. They can change without affecting the higher-level parts. Top-down cons: not everything has an easy to identify top (e. g. an os, low-level technical details can affect parts higher up in the hierarchy and cause problems. Identifies needed utility functionality early: promotes reuse of existing components.
