Wear Metrics

A wear metric is a quantitative measure used to assess the degree of wear of a component over time.

The wear level is a percentage value that starts at zero (the component is new) and increases day by day; and when it reaches 100%, it means it is time to replace the component, or the machine part subject to wear. The value can exceed 100% (e.g. 155%), which makes it possible to highlight critical situations, where even if a replacement is suggested, the machine continues to be used with a high risk of breakage, or poor quality of the final product.

The Wear Metric is based on a Wear Algorithm, you can use the default one (Time-based Wear Computation), or instead you can create your own.

Creating a Wear Metric

To add a new Wear Metric on a Thing Definition, you should:

• Enter the Insights / Wear Metrics page.

• Select the Thing Definition to edit.

• Press the Add Metric button.

• Select the Algorithm you want to use for the wear computation.
  Only algorithms that have the usage equal to Wear Metric can be selected.
  Press the Save button and edit the additional information.

Editing a Wear Metric

Once a Wear Metric has been created you can configure is properties. Other than inputs of the selected wear algorithm, you must provide additional wear information related to the maximum use to which the component/part can be subjected.

• Usage Unit: this is the label describing how the standard usage is measured. For instance, Working Hours, Nr. of Pieces, Cube Meters.

• Standard Usage: the standard use for which a certain component was designed.

• Tolerance: the extra use tolerated by the component, after which it is absolutely advisable to replace it.

• Worn Part Name: the name of the component, part subject to wear and tear (e.g. Oil Filter).

In the General section, you can specify these properties:

• Label: the metric label visible in the DPS.

• Name: the metric name used into templates.

• Group: the metric group name used to sort metrics.

• Description: the text describing what this metric is measuring.

Spare Parts Association

Optionally you can associate the wear metric to one or more Spare Parts used by the current Product Model. The same spare part can have different lifetimes depending on the product model in which they are installed.

When a Spare Part Reference is configured, you can optionally specify the Wear Metric and its Standard Usage and Tolerance.

Wear Metric Computation

As for the other insight metrics, the wear metric is periodically computed, generally after midnight, according to the time zone of the machine. For more details refer to the Periodic Evaluations article.

When the computation takes place, the wear calculation engine calculates the maximum usage to which a component/part can be subjected, taking into account what is defined in the metrics itself and optionally overridden on spare parts references.

Finally, the wear algorithm is executed by passing to it:

• the context as for other algorithms.

• the values of the inputs (e.g. Working Hours Metric).

• the Standard Usage the component/part may be subjected to.

• the Tolerance as allowed extra usage.

• the reached Usage, collected since the last replacement.

In the algorithm inputs, you can find the wearStatus node providing information about latest measured wear on a specific thing.

{
	"wearStatus": {
		"thingId": "661fabf042541977c4ff380c",
		"standardUsage": 100,
		"tolerance": 20,
		"usage": 74.36997,
		"wear": 61.974975,
		"lastReplaceTimestamp": 1715697321068
	}
}

The Wear Algorithm computes and returns the new usage value and the wear percentage, that will be saved in the new wear status object.

Wear Events and Involvement

When a wear metric is created, the Console automatically creates other configuration elements that are used to monitor and notify the wear status.

• Operation Event: An event that listens for wear status and is automatically triggered when the wear level exceeds the maximum usage specified in the wear metric or overridden by spare parts.

• Major Anomaly Event: an event listening on wear status that is automatically triggered when the wear level exceeds the maximum tolerated usage specified in the wear metric or overridden by spare parts.

• Replacement Action: a user action that triggers on one of the previous events and notifies the user of the need to purchase and replace parts.

Alerts are also generated for both events.

You can modify these elements (events, alerts and action) to provide the best experience for the user when replacing parts.

Wear Level Visualization

The value of a Wear metric can be displayed using the Wear Status widget, which provides the user with information about the wear component, its status, and suggested action.

In addition, you can use any widget supporting metric visualization, like:

• Value: to display a single value, also aggregated on a period.

• Time Series Chart: to display the trend on a period.