JSD Entity Structure Diagram

A JSD Entity Structure Diagram is a graphical representation of a system that is a part of the Jackson System Development (JSD) methodology. It is used to model the entities and actions within the system, as well as the relationships and interactions between them.

The diagram consists of a series of boxes (entities and actions). Entities represent the people, places, things, or concepts that are relevant to the system. These entities are connected by lines (connectors) with actions, which represent the processes or events that are carried out by the entities or affect other entities.

In addition to the basic entities and actions, the diagram may also include constructed actions, which are used to represent more complex interactions within the system. These include sequences, which illustrate a series of actions applied in a specific order; selections, which represent a choice between two or more options; and iterations, which represent actions that are repeated multiple times.

JSD Entity Structure Diagram Elements

Connector - A connector is used to link two entities or actions together in the diagram. It represents the relationship between the two elements and the flow of information or actions between them.

Entity - An entity represents an object that is used on or by the system. It is represented by a box in the diagram.

Action - An action represents a process or event that is carried out by an entity or affects another entity. It is also represented by a box in the diagram.

There are several types of action constructs:

• Sequence - An action sequence represents a series of actions that are applied in a specific order. It is represented by a simple box in the diagram.
• Selection - An action selection represents a choice between two or more options. It is represented by a simple box in the diagram, with the options marked in the top-right corner with a "o" (as option).
• Iteration - A iteration represents an action that is repeated multiple times. It is represented by a simple box in the diagram, with a small asterisk (*) in the top-right corner.