4.12.3 Resource Quantity
Resources may be defined according to a base quantity, where assigned tasks consume such amount of resource relative to an output quantity.
For work-based resources such as labor and equipment, quantities are based on time. For product-based resources, quantities are based on count. For material-based resources, quantities are based on volume.
The following diagram shows the generic classes and relationships used when applying this concept. In addition, concepts may have particular importance to common or standardised industry practices and scenarios. For these specific usage scenarios, the tables below shows a recommended list of general usage patterns that users may adopt.