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This article mainly introduces "the steps of building the UML use case model". In the daily operation, I believe that many people have doubts about the steps of building the UML use case model. The editor consulted all kinds of materials and sorted out the simple and easy-to-use operation methods. I hope it will be helpful to answer the doubts of "the steps of building the UML use case model". Next, please follow the editor to study!

Steps to build a UML use case model

In general, the steps to build a use case model are:

(1) to determine who will directly use the system, namely the participant (Actor), in order to find the participant, we can try to ask the following questions:

a. Who / what uses the system?

b. Who / what gets information from the system?

c. Who / what provides information to the system?

d. Who / what supports and maintains the system?

e. Which other systems use this system?

f. Which department of the company uses the system? .

(2) Select one of the participants

(3) define what the participant wants the system to do, and everything the participant wants the system to do becomes a use case. To find the use case, we can try to ask the following questions:

a. Why does the participant want to use this system?

b. Does the participant want to create, save, change, move, or read data from the system? If so, why?

c. Does the participant want to notify the system of external events or changes?

d. Does the participant need to know specific events within the system?

(4) for everything, when the participant will use the system and what usually happens is the basic process of the use case.

(5) describe the basic process of the use case.

(6) consider some variable situations and create them as extension use cases.

(7) Review the descriptions of different use cases, find out the similarities, and extract them as common use cases.

(8) repeat steps 2-7 to find each use case.

The reference criteria for actor checking in the UML use case model are as follows:

(1) have you found all the participants? That is, have you described and modeled all the actors in the system environment?

(2) does each actor involve at least one use case?

(3) can you list at least two people who can be specific participants?

(4) are there any participants acting as similar participants related to the system? If so, you should merge them into one participant.

The reference criteria for use case inspection are as follows:

(1) the introduction of the UML use case model provides a concise and clear overview of the purpose and function of the system.

(2) all use cases have been identified, and together these use cases illustrate all necessary actions.

(3) all functional requirements are mapped to at least one use case.

(4) the UML use case model does not contain redundant behavior, and all use cases can be traced back to some functional requirement to prove its rationality.

The use case diagram generally describes the various services that the system can provide, which makes us have an overall understanding of the function of the system, which is not enough. We also need to describe the details of each use case, that is, the use case specification. The use case model is composed of use case diagram and use case specification, which is a detailed description of each use case. A template for the use case specification is provided in RUP, which includes the following:

(1) brief description (BriefDescription): briefly introduce the function and purpose of the use case

(2) event flow (FlowofEvent): including basic flow and alternative flow, event flow should represent all scenarios

(3) use case scenario (Use-CaseScenario): includes success scenario and failure scenario, which is mainly composed of basic flow and alternative flow.

(4) SpecialRequirement: describe the non-functional requirements (including performance, reliability, availability, scalability, etc.) and design constraints (operating system, development tools, etc.) related to the use case

(5) Pre-Condition: the state that the system must be in before the use case is executed

(6) postcondition (Post-Condition): a set of states that the system may be in after the use case is executed.

The use case specification is basically expressed in text, and in order to describe the event flow more clearly, you can also choose to use state diagrams, activity diagrams or sequence diagrams to assist illustration (state diagrams help to describe state-related system behavior. activity diagrams help to describe complex decision-making processes, and sequence diagrams are suitable for describing message delivery based on time order. In addition, as long as it is helpful to express the use case succinctly, we can paste any user interface, graphical display of the process, and other graphics in the use case.

At this point, the study of "the steps to build a UML use case model" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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