UML多用于草稿 sketch
the UML 来自于 OO analysis and design methods。
某种程度上，
all of them mixed
a graphical modeling language
with a process that described how to go about developing software.
重点是 graphical language 和 process
Process 包括两种 iterative & Waterfall Process。
iterative process 无法预测，但是仍需要控制。
往往制定很多计划，the plan is treated as
a baseline to assess the consequences of change
rather than as a prediction of the future.
敏捷开发。
time boxing：slipping a date & slippping funcion 之间的平衡。
大多数人往往难以slipping function ——这是不是追求完美的倾向导致？
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Patterns 模式
The UML tells you how to express an object-oriented design.
Patterns look, instead, at the results of the process: example designs.
笔记未整理完