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來源1：Systems Engineering Tools and Methods
Ali K. Kamrani Maryam Azimi
Figure 3.7 shows the funcrion of a context diagram, here called an activicy unir, surrounded by orientation-specified inputs, outputs, controls, and enablers. Note that an activity unir can encompass and subsume a complete process.```
##### 來源2 INCOSE SEHB
This version of the handbook provides a high level view of the process‐of‐interest.
The diagram summarizes the process activities and their inputs and outputs from/to external actors; some inputs are categorized as controls and enablers.
- A control governs the accomplishments of the process;
- an enabler is the means by which the process is performed.