Use an example to create features:
By Jefong 2005/04/12
1. The use case is initiated by the end user or external environment of the system, the initiator of the use case is a participant (actor). Participants may be specific people or may be an external software system. 2. Each use will only describe a separate task without describing multiple tasks. The task described in the case must be in line with the user intention, complete work content. For example, for the software in the bank automatic teller machine, "Take money on the ATM" is a task that the user wants to complete, and "Enter Password" is just a step of this task. 3. The use case must produce a result of meaningful to the user. 4. A good use case should have good readability, which consists of multiple sentences, each using the same syntax form (a simple execution step). 5. The case view of the UML language can only reflect two types of information: (1) Which participants interact with our system? (2) What functional features do our system need to implement? 6. We should use the descriptive text or UML view or other form of view to summarize the specific procedure of the end user to complete a certain task, determine the order of the user operating system software and gets the expected results. 7. Scenario is an executive example of the use case, which is an actual path in the execution process. A use case may contain multiple scenarios, such as successful scenes, failed scenes. 8. In order to use the case to reach the requirements of the top three elements, use case modeling generally include the following steps: (1) Determine the system boundary; system "boundary" is separated from the functionality of the system with the external environment of the system. Logical boundary line. (2) Determine the participant; the system boundary separates the system and participants. (3) Find all the use cases; (4) Determine the level of each use case; the division of the selection of sections. The use case level includes: user target level use case, high-rise case (summary level case), sub-function level case. Note that do not mix the user interface and the user target level, each high-level use case may correspond to a software module, and the sub-function class has an inclusion and extended relationship. (5) Writing text description; (6) draws the sequence diagram of the entire system as an object;
