Thanks also to the js-sequence-diagram project for usage of the grammar for the sequence diagrams. Thanks to Jessica Peter for inspiration and starting point for gantt rendering. Mermaid was created by Knut Sveidqvist for easier documentation. Roles of the actors in the system can be depicted. Use Case Diagram: 4.4 Collaboration Diagram Collaboration diagrams remains analogous with the sequence diagrams since Diagrams encompasses various objects, links along with transmission or receiving of Messages in this way they coordinate to structural aspects of system.(which also provides.
Sequence Diagram: Sequence diagrams typically show the flow of functionality through a use case, and consist of the following components: 1. Actors, involved in the functionality 2. Objects, that a system needs to provide the functionality. UML Sequence diagrams are a dynamic modeling technique, as are collaboration diagrams and activity diagrams. UML sequence diagrams are typically used to. Validate and flesh out the logic of a usage scenario. A usage scenario is exactly what its name indicates - the description of a potential way that your system is used.
A use case diagramis 'a diagram that shows the relationshipsamong actors and use cases within a system. 'Use case diagrams are often used to:
A use case model is comprised of one or more use case diagrams and anysupporting documentation such as use case specifications and actor definitions. Within most use case models the use case specifications tend to be the primaryartifact with use case diagrams filling a supporting role as the 'glue' thatkeeps your requirements model together. Use case models should bedeveloped from the point of view of your project stakeholders and not from the(often technical) point of view of developers. There are guidelines for:
A use case describes a sequence of actions that provide ameasurable value to an actor. A usecase is drawn as a horizontal ellipse on a UML use case diagram, as you see in Figure 1.
Figure 1. Implying timing considerations between usecases.
An actor is a person, organization, or external system thatplays a role in one or more interactions with your system (actors are typically drawn asstick figures on UML Use Case diagrams).
Figure 2. Online shopping.
There are several types of relationships that may appear ona use case diagram:
Associations are depicted as lines connecting two modelingelements with an optional open-headed arrowhead on one end of the lineindicating the direction of the initial invocation of the relationship.Generalizations are depicted as a close-headed arrow with the arrow pointingtowards the more general modeling element.
Figure 3. Enrolling students in a university.
The rectangle around the use cases is called the systemboundary box and as the name suggests it indicates the scope of your system -the use cases inside the rectangle represent the functionality that you intendto implement.
A sequence diagram is a form of interaction diagram which shows objects as lifelines running down the page, with their interactions over time represented as messages drawn as arrows from the source lifeline to the target lifeline. Sequence diagrams are good at showing which objects communicate with which other objects; and what messages trigger those communications. Sequence diagrams are not intended for showing complex procedural logic.
A lifeline represents an individual participant in a sequence diagram. A lifeline will usually have a rectangle containing its object name. If its name is 'self', that indicates that the lifeline represents the classifier which owns the sequence diagram.
Sometimes a sequence diagram will have a lifeline with an actor element symbol at its head. This will usually be the case if the sequence diagram is owned by a use case. Boundary, control and entity elements from robustness diagrams can also own lifelines.
Messages are displayed as arrows. Messages can be complete, lost or found; synchronous or asynchronous; call or signal. In the following diagram, the first message is a synchronous message (denoted by the solid arrowhead) complete with an implicit return message; the second message is asynchronous (denoted by line arrowhead), and the third is the asynchronous return message (denoted by the dashed line).
A thin rectangle running down the lifeline denotes the execution occurrence, or activation of a focus of control. In the previous diagram, there are three execution occurrences. The first is the source object sending two messages and receiving two replies; the second is the target object receiving a synchronous message and returning a reply; and the third is the target object receiving an asynchronous message and returning a reply.
A self message can represent a recursive call of an operation, or one method calling another method belonging to the same object. It is shown as creating a nested focus of control in the lifeline’s execution occurrence.
Lost messages are those that are either sent but do not arrive at the intended recipient, or which go to a recipient not shown on the current diagram. Found messages are those that arrive from an unknown sender, or from a sender not shown on the current diagram. They are denoted going to or coming from an endpoint element.
A lifeline may be created or destroyed during the timescale represented by a sequence diagram. In the latter case, the lifeline is terminated by a stop symbol, represented as a cross. In the former case, the symbol at the head of the lifeline is shown at a lower level down the page than the symbol of the object that caused the creation. The following diagram shows an object being created and destroyed.
What is your ip addresses. By default, a message is shown as a horizontal line. Since the lifeline represents the passage of time down the screen, when modelling a real-time system, or even a time-bound business process, it can be important to consider the length of time it takes to perform actions. By setting a duration constraint for a message, the message will be shown as a sloping line.
There is also an interaction occurrence, which is similar to a combined fragment. An interaction occurrence is a reference to another diagram which has the word 'ref' in the top left corner of the frame, and has the name of the referenced diagram shown in the middle of the frame.
A gate is a connection point for connecting a message inside a fragment with a message outside a fragment. EA shows a gate as a small square on a fragment frame. Diagram gates act as off-page connectors for sequence diagrams, representing the source of incoming messages or the target of outgoing messages. The following two diagrams show how they might be used in practice. Note that the gate on the top level diagram is the point at which the message arrowhead touches the reference fragment - there is no need to render it as a box shape.
An object can have more than one lifeline coming from it. This allows for inter- and intra-object messages to be displayed on the same diagram.
A state invariant is a constraint placed on a lifeline that must be true at run-time. It is shown as a rectangle with semi-circular ends.
A continuation has the same notation as a state invariant, but is used in combined fragments and can stretch across more than one lifeline.