uml--use case diagram

One. UML Overview

The role of 1.UML: a complex problem decomposition B realizes the visualization

UML is created by rational company 2.UML is what: is a language, has its own standard expression rules, is an analytical design language, is also a modeling language 3.UML including five large views, 13 kinds of Figure five views: User view: use case diagramBehavior View:sequence diagram, state diagram, activity diagram, communication diagram, timing diagram, interactive overview graph structure view: class Diagram , package diagram, object graph, combined structure diagram Environment view:deployment DiagramImplementation view:Component Diagram       The most frequently used is the use case diagram and Class diagram two. UML Construction Requirements Model         drawing use case diagram--"Writing use case document-" Checking use case Model-"state diagram, activity diagram, sequence diagram          use case modeling techniques mainly include:  1. Drawing use case diagram  2. Writing use case documentation            1. Drawing a use case diagram                    a Find performers:                                     There are three categories of performers:    people; other systems; events that occur automatically                    b Find Use Cases:                                  performed in the systemA series of actions，The system will generate visible value results                             Use cases are usually described from the user's perspective; The use case is named: (adverbial) verb + (attributive) objectuse case granularity: Granularity principle: Use case to have path, path must have step                                                                  basic path refers to: All actions are correct path                                      except for the base path: Extension path: Includes alternate path and exception path                                      such as go to the supermarket to buy things, cash payment is the basic path, without cash can be paid by credit card is the alternative path,                         &nbThe sp;                 is the exception path.                          c    Find out performers-use cases, performers-performers, use cases-relationships between use cases                                    Performers-use cases:   Association Relationships (Association)                                    performer-Performer: generalization relationship (inheritance relationship)                                                   

 

                                        Use cases--use cases {  include relationships, extended relationships, generalized relationships}                                         include relationship    For example, the educational administration system, students want to check the timetable, check the results, check the rankings, must first sign up                                          Land, So check the timetable, check the results, see the rankings include the landing                                           

Extended relationship: To declare a specific extension point

Generalization relationships: You often use extended relationships instead of generalization exercises:a hotel reservation system is described as follows:

(1) customers can choose to Book online , or directly to the hotel through the front desk waiter booking;

(2) front desk staff can use the system to book rooms directly at the front desk ;

(3) Regardless of the booking method, you will need to pay the corresponding deposit at the time of booking;

(4) The front desk reservation can be paid by cash or credit card , but the online booking can only be paid by credit card;

(5) Communication with credit card system is required for payment with credit card;

(6) Housekeeping Manager can check the room reservation status and daily collection status at any time.

Construct the use case model of the system.

uml--use case diagram