图 Steps Decompose the functional specification into functional units -Characteristics of functional units They can be tested independently ·Examples -A top-level user command Or a function Decomposition may require several stages Similar to high-level decomposition done by software designers May be reused,although independent decomposition is recommended >校长办公室 >Office of the President¾校长办公室 ¾Office of the President Steps • Decompose the functional specification into functional units – Characteristics of functional units • They can be tested independently • Examples – A top-level user command – Or a function • Decomposition may require several stages • Similar to high-level decomposition done by software designers – May be reused, although independent decomposition is recommended