Entity Relationship Diagram ERD Technique

In the IT environment, it is at times necessary for analysts to use an entity relationship diagram (ERD) to document and model organizational information needs. Sometimes narrative descriptions cannot be used, as it can be difficult to visualize the vast amounts of data and processes in a textual format. The ERD allows the analyst to visually model the organization's information needs during the early stages of the SDLC. When constructing an entity, the project manager writes the entity's name (i.e., Customer or Employee) into rectangular boxes, which denote them as entities. Another class of object in an ERD is a relationship. Entities are also associated by relationships that represent real-world relationships (see Figure 4.1). The following are some tips for using ERDs:

Entities are objects about which the system needs to record information.

Relationships are recorded on the diagram as verbs and are represented by a diamond shape.

Places

Places

Figure 4.1: Basic entity relationship diagram

Figure 4.1: Basic entity relationship diagram

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