These are countable units which may be comprised of one or more raw asset data items. You create usage items in the Usage application and then create the data components (a combination of model, data item, and type) from which they get their values. Each usage item must have a unique name in the Axeda® Platform. When you add a data item to a usage item, the model for that data item is now related to the usage item within the bounds of the applications. For example, you can create a "Set Usage Item Value" action (from the Configuration application); however, only usage items related to the selected model can be configured within this action.
A usage item is a metric that provides a way to track asset-specific countable items or operations (uses) across multiple models. For example, you can create usage items that track black and white copies made, pages printed, or blood tests performed. Each of these usage items can be applied to all models that perform those operations and for which you want to track counts or uses.
For each usage item, two values are captured in the Platform: a running total for the specific asset for the usage item (actual value) and the change in value from the last reading (delta value). These are defined in the Usage application as Cumulative and Incremental, as follows:
1. Incremental - contains the current actual reading of the usage item. This contains the changed value of the countable item, from the previous sampling.
2. Cumulative - contains the amount of change in the value between two points in time for this usage item. This contains the total value of the countable item.
You can configure a usage item to be the Cumulative value (running total) or the Incremental (delta value) for the related counts. An example of this is when the Enterprise server is reading the value of a countable data item. If the first reading is 500 and the second reading is 750, then a usage item tracking the incremental type for this data item will reflect the delta value of 250. You can perform analytics searches specific to a usage item type.
Access to usage item information is limited to those user groups (and subsequent users) with rights to the related model. For example, if a usage item is defined for several models, a user needs to have security rights to at least one of those models to be able to "see" that usage item in the Axeda® Connected Product Management Applications.
For information about security for usage items, refer to Security for Objects in Axeda® Connected Product Management Applications and for information about security for these objects when Delegated Administration is enabled, refer to Security for Objects in Delegated Administration Units.
In a Platform with Delegated Administration enabled, the names of usage items may have prefixes; for details, refer to Names of Objects in DA Units.