Entity-Relationship Diagram (ERD)

"Chen's notation for entity–relationship modeling uses rectangles to represent entity sets, and diamonds to represent relationships appropriate for first-class objects: they can have attributes and relationships of their own. If an entity set participates in a relationship set, they are connected with a line.
Attributes are drawn as ovals and are connected with a line to exactly one entity or relationship set.
Cardinality constraints are expressed as follows:
- a double line indicates a participation constraint, totality or surjectivity: all entities in the entity set must participate in at least one relationship in the relationship set;
- an arrow from entity set to relationship set indicates a key constraint, i.e. injectivity: each entity of the entity set can participate in at most one relationship in the relationship set;
- a thick line indicates both, i.e. bijectivity: each entity in the entity set is involved in exactly one relationship.
- an underlined name of an attribute indicates that it is a key: two different entities or relationships with this attribute always have different values for this attribute.
Attributes are often omitted as they can clutter up a diagram; other diagram techniques often list entity attributes within the rectangles drawn for entity sets." [Entity–relationship model. Wikipedia]
The vector stencils library ERD, Chen's notation contains 13 symbols for drawing entity-relatinship diagrams using the ConceptDraw PRO diagramming and vector drawing software.
The example "Design elements - ER diagram (Chen notation)" is included in the Entity-Relationship Diagram (ERD) solution from the Software Development area of ConceptDraw Solution Park.

"Crow's Foot notation is used in Barker's Notation, SSADM and Information Engineering. Crow's Foot diagrams represent entities as boxes, and relationships as lines between the boxes. Different shapes at the ends of these lines represent the cardinality of the relationship." [Entity–relationship model. Wikipedia]
The vector stencils library ERD, crow's foot notation contains 18 symbols for creating the ER-diagrams using the ConceptDraw PRO diagramming nd vector drawing software.
The example"Design elements - ERD solution (crow's foot notation)" is included in the Entity-Relationship Diagram (ERD) solution from the Software Development area of ConceptDraw Solution Park.

"Interrelationship Digraph (ID).
This tool displays all the interrelated cause-and-effect relationships and factors involved in a complex problem and describes desired outcomes. The process of creating an interrelationship digraph helps a group analyze the natural links between different aspects of a complex situation." [Seven Management and Planning Tools. Wikipedia]
"Causality (also referred to as causation) is the relation between an event (the cause) and a second event (the effect), where the second event is understood as a consequence of the first.
In common usage, causality is also the relation between a set of factors (causes) and a phenomenon (the effect). Anything that affects an effect is a factor of that effect. A direct factor is a factor that affects an effect directly, that is, without any intervening factors. (Intervening factors are sometimes called "intermediate factors".) The connection between a cause(s) and an effect in this way can also be referred to as a causal nexus.
Though the causes and effects are typically related to changes or events, candidates include objects, processes, properties, variables, facts, and states of affairs; characterizing the causal relation can be the subject of much debate." [Causality. Wikipedia]
The relations diagram example "Health care" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the solution "Seven Management and Planning Tools" from the Management area of ConceptDraw Solution Park.