Schedules [PWS]

Purpose and Scope

Some feature properties may have their own cyclic variation in time according to an established schedule. For example, a navaid can be operational during day time and unserviceable during night time, etc. To model such situations, the concept of “properties with schedule” has been introduced since AIXM version 5.1. It associates one or more properties that have cyclic varying values with "timesheets”, which identify the times when these properties have specific values. At the feature level, all the properties that change according to the same schedule are in a separate class, which inherits the necessary attributes and relationships from an abstract class called "PropertiesWithSchedule". For example, the working hours of a navaid are modelled through the NavaidOperationalStatus class, which associates a status attribute with the Timesheet inherited from the PropertiesWithSchedule class, as visible on the diagram below.