[许迈克]

It said to help system designer focus on satisfying user's needs.

Shall we include more details?

For example:

We are developing a poker game. The rule is : first, player will get 5 cards, then hold some of them, and ask system to draw and change those which are not hold.

the Use Case for this situation could be 2 ways:

way 1,
system-----deal(generate 5 cards)
player------hold
system------draw( player will get 0 to 5 new cards)
way 2,
system-----generate cards
player ----- hold

[许迈克]

which way is better?

[xianese]

Use Cases当然是越细越好，这样有利于生成更符合实际的模型。

一般而言，Use Cases有两个方面，System和与System打交道的client.

根据你的描述，我觉得Use Case应该这样写：

Use case name: whatever

1. PLAYER ask cards from SYSTEM(start)
2. PLAYER gets 5 cards generated by SYSTEM
3. PLAYER select some cards and returns rest to SYSTEM
4. PLAYER gets new cards drawn by SYSTEM
...

至于SYSTEM是如何得到这些cards，就不在考虑的范围了。重点是PLAYER和SYSTEM是怎样互动的。

希望有所帮助。

[许迈克]

xianese 写道:

Use Cases当然是越细越好，这样有利于生成更符合实际的模型。 一般而言，Use Cases有两个方面，System和与System打交道的client. 根据你的描述，我觉得Use Case应该这样写： Use case name: whatever 1. PLAYER ask cards from SYSTEM(start) 2. PLAYER gets 5 cards generated by SYSTEM 3. PLAYER select some cards and returns rest to SYSTEM 4. PLAYER gets new cards drawn by SYSTEM ... 至于SYSTEM是如何得到这些cards，就不在考虑的范围了。重点是PLAYER和SYSTEM是怎样互动的。 希望有所帮助。

Quite clear, good one!