None of the circled terms exists in isolation. They all relate to each other in one or more ways. Understanding these relationships is the next step in Vocabulary construction. The following facts are observed or inferred from the example:

  • An aircraft carries a cargo shipment.
  • A flight plan schedules cargo for shipment on an aircraft.
  • A cargo shipment has a weight.
  • A cargo shipment has a manifest number.
  • An aircraft has a tail number.
  • An aircraft has a maximum cargo weight.
  • A 747 is a type of aircraft.

Notice that some of these facts describe how one term relates to another term; for example, an aircraft carries a cargo shipment. This type of statement usually provides a clue that the terms in question, aircraft and cargo shipment, are entities and are two primary terms.

Also notice that a fact “has a” relationship. For example, an aircraft “has a” tail number, or a cargo “has a” weight. This type of relationship usually identifies the subject (aircraft) as an entity and the object (tail number) as an attribute of that entity. By continuing the analysis, the Vocabulary contains 3 main entities, each with its own set of attributes:

Entity: Aircraft

Attributes: aircraft type, max cargo weight, max cargo volume, tail number

Entity: Cargo

Attributes: weight, volume, manifest number, packaging

Entity: FlightPlan

Attributes: flight number