UML Modeling

UML is one of the most popular language of modeling.


UML (Unified Modeling Language) is intended for the simplification of the communication and the interaction between the project participants, for the reduction of the time spent on the explanation and the assimilation of information, for the documents simplification.

UML is a graphical notation, which is intended for describing and modeling the processes, which flow during the development process. The diagrams of this notation have different types and describe various development aspects. There are 2 main types of UML-diagrams: structural and behavioral.

Structural diagrams show the elements the system consists of. Behavioral models describe the processes that occur in the system. You can order uml diagrams from an experienced mobile app development firm.

Each language of modeling has its own glossary. The UML glossary consists of the following elements:

  • Entities are the abstracts, which are the main elements of models;

  • Relationships are the connections between entities;

  • Diagrams are the reflection of the interactions between entities and relationships.

 

1.Entities.

There are 4 types of entities in UML:

  • Structural entities are the nouns of model, its static parts. These are the classes, components, interfaces, etc., which correspond to the physical elements of the system.

  • Behavioral entities are the verbs of the model, describe its behavior in time and space. There are 2 types of behavioral entities: an interaction (the exchange of messages) and an automation (the sequences of states).

  • Annotation entities are the explanatory parts of the model. These are notes and comments on the elements of the system.

  • Grouping entities are the organizational parts of the model. They organize the elements of the system into groups.

 

2. Relationships.

There are 4 types of relationships in UML:

  • Dependency is the relationship between two entities, in which the changes in one of them (independent) entity leads to the changes in the second entity. It is shown graphically as a dotted arrow.

  • Generalization is the relationship "specialization-generalization," where a specialized object can be constructed instead of a generalized object.

  • Association is the relationship, which describes the semantic connection between the objects. It is shown graphically as a solid arrow, which can contain multiplicity or the name of roles. (Aggregation is the differentiation of association and shows the part-to-whole ratio).

  • Composition is the differentiation of the aggregation, where the connection between the parts and the whole is stronger.

  • Realization is the relationship between the classifiers, in which one of them  determines the obligation, and the other ensures its fulfillment.

 

3. Diagrams.

There are 10 types of diagrams in UML:

  • Object;

  • Class;

  • Interaction:

  • Use-case;  

  • Sequence;  

  • Statechart;

  • Collaboration;

  • Component;

  • Deployment;

  • Activity.