The use case model should place the system in context, showing the boundaries of the system and the external actors as well as describing the key interactions between the system and the actors.

用例模型应该将系统放到上下文环境中，显示系统和外部参与者之间的边界，并描述系统和参与者之间的关键交互。

youdao

Don had been an administrator in the Little Rock system a few years earlier, so he knew a lot of the players, and he had a friendly, low-key manner and got along well with most of them.

几年以前，他还在小石城做过行政管理工作。 对那里的各方面的人物都非常熟悉，他待人友好、举止低调，和多数人相处得很好。

youdao

The post shows the four key habits for maintaining a comprehensive system for all your information and tasks, as well as my current setup.

为你所有的信息和任务建立综合系统，需要4个关键习惯，我现在也是这么做的。

youdao

The operational intelligence system monitored the entire end-to-end process as well as key milestones in each system.

FORBES: New Sources for Business Surprises

Dr. ORSZAG: Well, the key to our long-term fiscal future is actually improving the efficiency of the health care system, and I think there's a lot that can be done there to bring - to bend the curve on health care costs.

NPR: Orszag Eyes Swift Spending Of Stimulus Funds