Linear Assets (3) – Asset Features

This article uses features on a linear asset in the Features tab on the Assets application and includes the asset feature’s specification

Assets Application – Features tab

With the features created you can now add them to the linear asset in the Features tab of the Assets application. I-95N has 12 asset features, 10 Mile Posts and 2 Guard Rails. 

A Feature that exists on an asset I call an Asset Feature, so that the term Feature can refer to a record in the Features application. An alternative is to call the feature on an asset record a Feature, and the record in the Features application a Feature Class. It is worth distinguishing between the two records, just calling both record types Features will lead to confusion.

When an Asset Feature has no Feature Label, it is referred to as a generic asset feature. I think it probably best to always add a Feature Label, to make a distinction between multiple asset features on the same linear asset that reference the same feature. Notice, I used the term Feature Label, you needn’t say Asset Feature Label. A record in the Features application does not have a label.

When you use the New Row button and pick the feature from the Select Value the details of the feature and its specification will be copied to the asset feature. For example, attribute HEIGHT, the value 3.0 was copied from the HEIGHT attribute of the GUARDRAIL feature.

You can now add the measures that position the asset feature and modify the asset feature’s attribute values particularly for attributes with no corresponding value on the asset feature’s specification. 

I have opened the details section for the Asset Feature of the first Mile Post – MP 10. It has a Type of POINT and no classification, it is Shared with Related Assets and is a Reference Point, these details are all copied from the Feature called MP. Notice you could add a classification to the asset feature, it does not need to be derived from the feature record, but this would be unusual. 

In the Linear Segment Details, you need to position the mile post, MP 10. In this case, it is an absolute measure that occurs at 10.00 MILES from the start of the linear asset. As it is a POINT type you do not get the ability to enter the End measure, only the Start measure. Notice the Y Reference and Z Reference and the unit of measures have been copied from the descriptions you gave in the Action Add/Modify Linear Referencing Methods. Notice, also, that for POINT features the attributes for the End measure are all read-only.

Below the attributes for the asset feature is the linear visual control. This shows the linear asset’s features MP and GUARDRAIL as two separate rows positioned according to the start and end measures. The Zoom Level is showing 10s of the x-axis unit of measure (MILES) – Zoom to tens. Each point asset feature is shown as a yellow diamond, and each linear asset feature is shown as a yellow bar and positioned according to its start and end measure. If you hover over any of the symbols a balloon tip message is shown. In the example this is the feature description followed by the title Start Measure and its value followed beneath this with the title of End Measure and its value. The Guard Rail is positioned between 20 and 25 miles from the start of the linear asset.

Organizations – Asset Options – Features

The Label and Balloon Tips are configurable from the Organizations application and action Asset Options. 

The Balloon Tip Measure for a Feature is:

#{[--#{attributeTitle|STARTMEASURE}: ${startmeasure}--]}
#{[--#{attributeTitle|ENDMEASURE}: ${endmeasure}--]}

You can see that the Balloon Tip Message shows the value of FEATURE.DESCRIPTION in bold followed by two lines that include the STARTMEASURE and ENDMEASURE attributes and their values, e.g. ${startmeasure} and ${endmeasure}.

Assets Application – Features tab – Asset Feature Specifications

The Asset Feature’s Specification does not need to be the same for the whole length of the asset feature. For the second GUARDRAIL feature between 20.00 and 25.00 miles there are two MATERIAL and two BEAM attributes.

We saw that the Asset Feature had a section called Linear Segment Details, an attribute of its specification also has a section for Linear Segment Details.

The first MATERIAL attribute is made of ALUM (Aluminium) between 20.00 and 23.00 miles, and you’ll find that the BEAM is of type “W Beam” over the same distance.

If you go down to the linear visual control and in the description column you open the details for the GUARDRAIL features, then you see for the second Guard Rail that the asset feature specification attributes for BEAM shows a change from W Beam to Thrie Beam at 23.00 miles.

The MATERIAL attribute for the same Guard Rail looks like a mistake in the data as it is showing IRON for the whole length from 20.00 to 25.00 miles, I suspect this should be for the length 23.00 to 25.00. Without the linear visual control, it would be very difficult to spot data issues.

I’ve corrected the data and hovered over the bar to see the balloon tip message for the MATERIAL attribute between 23.00 and 25.00 miles, and it is now showing it is of IRON construction.

Organizations – Asset Options – Feature Specifications

In the Organizations application for the Asset Options action, you’ll find you can configure the Label and Balloon Tip Message for the Feature Specification as well.

Assets Application – View Feature History

There is an action called View Feature History which opens a dialog and displays the features of the linear asset. Notice the As of field is set to the current date and time and we are looking at all the features. 

The Features table window shows three GUARDRAIL features, but we know we only have two. This is because there is an Asset Feature History table (ASSETFEATUREHIST) and this is what we are looking at. If you make a change to the positioning of a feature it creates another record in the Asset Feature History table.

Incidentally, I cannot see any difference between the 2nd and 3rd GUARDRAIL history records except the date and time the record was created, and I think the 3rd GUARDRAIL record should have a Removed Date, I’ll explain why in a second. I suspect this is an anomaly in the MAXDEMO database.

In the top section I have changed the View Segment From and To fields to focus on the features in the section of the linear asset between 15.00 and 30.00 miles. For the GUARDRAIL feature we can now see the five attributes of the asset feature specification.

The MATERIAL attribute of the GUARDRAIL between 23.00 and 25.00 miles is showing as IRON type. We changed this a little while ago.

If I change the As of date and time to a time of 09:00 this morning you can see that the MATERIAL attribute of type IRON was from 20.00 to 25.00 miles. The Removed Date in the Attributes table window indicates that something on this attribute record was changed at 11/02/22 10:19 this morning, we know that was the Start Measure. 

When a value is changed on a record with a history the Removed Date is normally set. This is why I think the 3rd GUARDRAIL feature should have a Removed Date, if it did it would not be displayed when you first come into the View Feature History dialog, it is not a current record, it has been removed, consequently it shouldn’t be displayed.

The View Feature History action allows you to see both the changes to the feature and its specification at any point in time, whether they are measure changes or attribute value changes. 

Shared Features

When you add a feature to a linear asset the Shared field on the Feature is copied to the Share With Related Assets on the new asset feature record. You can see that all the MP – Mile Post asset features for I-95N are being shared with other linear assets that are related to the linear asset over a part of its length.

If you look at the linear asset I-95S the Share With Related Assets is checked for MP – Mile Post features, it is also read-only and the On Related Asset is checked for these Mile Posts. This occurs for I-95S because the whole length has a relationship to I-95N, the relationship is PARALLEL. These mile posts are being shared with I-95S because of the relationship with I-95N.

If a linear asset shared a stretch of I-95N between 15.00 and 35.00 miles, say with a relationship of BECOMES then MP 20 and MP 30 would be shown as shared features.

Reference Points

I’ve just added a new feature to I-95N another GANTRY-LCD, a point feature positioned -2,000 FEET before Mile Post 30 (MP 30) which is marked as a Reference Point. A GANTRY-LCD feature is not a reference point, the Is Reference Point was initially blank, but I can make this new GANTRY-LCD asset feature a Reference Point and use it to measure work or reference meters or attributes from it. You can create new asset features as reference points using other features as their reference point.

I can remove the Reference Point from asset feature MP 30. This has no effect on other asset features which used it as a reference point, it’s just that you could not use MP 30 as a reference point in the future.

Note. If I want to navigate from GANTRY-LCD to the Features application with the feature of the same name, it did not find the record. It will launch the Features application, the Where clause was ((islinearref = 1 and classstructureid = ‘1340’ and shared = 0 and feature = ‘GANTRY-LCD’)) and (1=1). This seems incorrect and I have raised a case with IBM Support.

Created by Relationship

On a different linear asset MD 414 which intersects with I-95N and I-95S the Feature INTERSECTS with a Feature Label of MD 414 INTERSECTS I-95S has been created automatically and the Created by Relationship is checked. The Feature Label has been generated from an associated relationship on the linear asset, this relationship is defined by the attribute ASSETLOCRELATIONNUM which is a hidden field.

The Asset Feature long description reads:

Notice the Is Reference Point is also checked when the asset feature is automatically created from a relationship. You might also notice that the Linear Segment Details fields are read-only, the position of the feature on the linear asset is being controlled from the associated relationship.

The automatically created feature occurs when Use As Reference is checked on a Relationship in the Relationships tab. Its field help says “Specifies whether you can use the relationship as a start or end point for a linear segment. If the check box is selected (the default), Maximo will create a feature instance that you can use as a start or end reference point. If the check box is cleared, you cannot.”

When a couple of roads have bridges over a highway the grass verges between these roads may set up an area, a linear segment, that is used for grass mowing and other work. Therefore, intersections will often be marked as becoming Reference Points, and the asset feature is created automatically.

To illustrate, we will check the Use As Reference field on the relationship between MD 414 and US 50.

In the Features tab we have an additional asset feature created automatically, the new INTERSECTS asset feature has the generated feature Label of MD 414 INTERSECTS US 50 and the two check boxes Is Reference Point and Created by Relationship are both checked.

Incidentally the Use As Reference checkbox on the Relationships tab is the attribute ISLINEARREF, this is populated from the field in the Relationships application called Is Reference Point. If the Use As Reference is unchecked then the automatically created asset feature is deleted.

If you uncheck the Created by Relationship field, then an information message with OK and Cancel buttons is displayed “INTERSECTS was created from asset relationship that is marked as reference point. If you modify the created by relationship, then there is no link between the asset feature and asset relationship. Do you want to continue? (BMXAA7461)”. If you use the OK button the ASSETLOCRELATIONNUM attribute will be made null, it has been delinked, and the asset feature fields become editable. The asset feature is not deleted, and it remains a reference point.

Continuous Features

In the article Linear Assets (2) – Features we gave an example of a continuous feature as the lane of a highway. For I-95N I’ve created three LANE features with different asset feature labels, Lane 1, Lane 2 and Lane 3.

When creating the feature, you still need to enter the Start and End Measure which will normally align with the start and end of the linear asset, 0.00 and 109.70 in this case. The Continuous checkbox is populated from the corresponding Feature LANE, but on the asset feature record it is read-only. Notice that the Is Reference Point checkbox is also read-only.

In the Linear Visual Control, you can see the three continuous lanes. The label on the yellow bar is the asset feature’s label. If this is null, then the feature’s description is used instead, it would be Lane of a Highway. 

The field help of the Continuous attribute of the asset feature’s record reads “Specifies whether the feature is continuous. If the check box is selected, it is continuous. A continuous feature exists for the entire span of the linear asset with which it is associated. To satisfy this condition you can create a single Features record whose start and end measures equal the start and end measures of the linear asset. You can also create multiple Features records that together cover the entire linear asset without overlapping. To validate this property, run the Gap and Overlap report. If the check box is cleared (the default), you can apply the feature to a segment of the linear asset.”

I’ve added three more LANE features, with labels, Lane 4A, Lane 4B and Lane 4C to form one continuous feature. This is an example for the 2nd part of the field help, the phrase “You can also create multiple Features records that together cover the entire linear asset without overlapping”.

Report – Linear Gap and Overlap

The Linear Gap and Overlap report can be run for a single linear asset and site. The Asset prompt is mandatory, and it only accepts a single asset.

When run for the continuous features of I-95N it shows one Overlap from measure 0-30. The features which are overlapping are Lane 1, Lane 2, Lane 3, and Lane 4A. The second section shows the Overlap from 40-109.7 and shows just Lane 4C. I confess at this stage to not fully understanding the report.

I then moved Lane 4B to start from the Reference Point MP 20 at 20 miles creating an overlap between 4A and 4B between 20 and 30 miles. The Linear Gap and Overlap report show the same information for the first section from 0-30 and the last section from 40-109.7. However, a second section now appears as an Overlap between 20-30 for Lane 4B. Still uncertain about the report.

Finally, I introduced a gap between Lane 4A and Lane 4B by shortening Lane 4A to between 0-15 miles.

The Linear Gap and Overlap report now show three overlap sections with the measures for Lane 4A (Overlap 0-15), Lane 4B (Overlap 20-40) and Lane 4C (Overlap 40-109.7). There is also a Gap identified between 15-20 and it shows Lane 4A (0-15) and Lane 4B (20-40). This looks more understandable. 

However, what I do not understand is the following:

I will raise a case with IBM Support and see whether the report can be explained.

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