This article will take a reader through the Features application but will also describe some changes made in the Classifications application to support linear assets and features.
A feature is a class of physical object that you will find along a linear asset. For example, along a road you will find mile posts, guard rails and overhead gantries. A feature is not an asset, there would not be a serial number, and you would not collect costs against it, but there may be point assets that uses the feature as a reference point, and you may perform work on the features but in this case, you are booking time to the linear asset. For example, there are several gantries on a road, some of these have road signs showing distances to cities and towns, other gantries have a set of LCD lane displays which are point assets. Each gantry is a feature which identifies where it is along the road, the linear asset. An inspection can be performed on the gantries for a stretch of the road, this is an inspection of the gantry itself rather than the LCD lane display assets.
The Features application’s List tab has columns for the Feature, its Description, its Type, and check boxes for Shared and Continuous which we will explain in a second. There are two types, POINT and LINEAR.
A Feature is defined at the System level, consequently not all features will be used by the Site where your linear assets are located, some may be for other linear uses in your enterprise. For example, TIES are used with railways and is unlikely to be used by the site where you have roads to maintain.
A Feature does have a status, but it is not shown. There is a STATUS field with a Synonym Domain FEATURESTATUS with values of NOT READY, OPERATING and DECOMMISSIONED, and there is a Status History table FEATURESTATUS. But there are no actions for Change Status or View History. If a status is required, it could be configured. If a feature is changed to a status of DECOMMISSIONED, it will no longer be available to reference on a linear asset.
If a feature has been referenced on a linear asset you will not be able to delete it, you will receive the error message “BMXAA5266E – Cannot delete feature GUARDRAIL because it is referenced by a Linear Asset.”. You cannot delete a feature if it is or has been referenced on a linear asset, i.e., there is history of the feature existing on the linear asset.
Feature – Point Type
A Mile Post is an example of a POINT type, the Type field is mandatory. The Continuous checkbox will be read-only as this is only used with the LINEAR type.
The Mile Post (MP) has been defined as a Reference Point. When this type of feature is used on a linear asset its position will have an accurate absolute measure from the start of the linear asset and consequently can be used to measure other features, assets, or work, from this reference point. For example, a pothole may exist 122 feet from the reference point MP 30.
The Shared checkbox is used to allow a feature to be used by multiple related linear assets. For example, two linear assets that run in parallel, I-95N and I-95S can share the same mile posts. If the feature is applied to one linear asset it will be visible to the related linear assets. The sharing of features only occurs for the distance along one linear asset where the other linear asset is related.
A feature can have a classification and a specification. A mile post has no useful characteristics worth being recorded by the maintenance department, and the classification is left blank.
When a feature has been used on a linear asset it will be referenced as a row in the Where Used tab. For asset I-95N it exists 10 times at mile posts every 10 miles along I-95N. As the feature type is POINT the Start Measure and End Measure are the same. You apply the feature to the asset in the Assets application, there is no New Row or Delete Row buttons on the Where Used tab.
Feature – Linear Type
The GUARDRAIL is an example of a LINEAR type of feature, the guard rail has length and when referenced on a linear asset will have a Start Measure and an End Measure that are not the same.
Only LINEAR type features can be marked as Continuous, which means that this type of feature exists for the whole length of the linear asset. The Guard Rail in this instance is not marked as continuous, it could be, but more often a Guard Rail exists for small stretches of road, perhaps where the ground falls away the other side or there is a ditch.
An example of a continuous feature would be a LANE of a motorway. The feature exists for the whole span of the linear asset. You can enter the LANE feature multiple times for the same linear asset and provide an asset feature label, for example Lane 1, Lane 2, Lane 3. There is an example of this in the article Linear Assets (3) – Asset Features.
If a lane does not exist for the whole length of a linear asset, then give it a different feature name and do not mark it as continuous. For examples there may be an additional overtaking lane on hills of some highways to allow cars to overtake slow moving lorries, in which case create a new non-continuous linear feature like OVERTAKINGLANE – Overtaking Lane.
A LINEAR type of feature could be made a Reference Point, but it would be unusual. However, when one linear asset intersects or crosses over another linear asset that could be a reference point. A Relationship can be marked as a Reference Point and this will automatically create a LINEAR feature where the Is Reference Point is checked, this will be discussed in Linear Assets (5) – Relationships.
Note. When inserting a new feature, the default type is LINEAR, and Reference Point is checked.
The GUARDRAIL feature has a Classification and three attributes, HEIGHT, MATERIAL, and BEAM. The classification is often made the same name as the feature. I don’t think there would be a need for a feature classification unless you were also going to create attributes for the classification, its specification.
This works the same as for other classifications/specifications in Maximo but there are two fields on an attribute used by linear assets which we will explain shortly.
The GUARDRAIL has been used on linear asset I-95N in three places. Notice on the Where Used tab the Start Measure and End Measure are different, the feature has length. Notice that the last two records look as if the feature exists on asset I-95N twice at the same position, it doesn’t.
The Where Used tab is showing the Asset Feature History rather than just the Asset Features. It is only showing the latest position of the asset feature, one where the ASSETFEATUREHIST.REMOVEDDATE is null, there is an issue with the MAXDEMO database. If you are configuring this table window, I would place the Start Measure column before the End Measure column.
I’ve created a new feature GANTRY-SIGN – Gantry,Road Signs of type POINT which I aim to use later.
This feature has a new classification GANTRY \ ROADSIGN with attributes for Material, Length, Height, Gantry Type and Cantilever Type. In this case the GANTRY-SIGN feature is of steel construction, a bridge 32 feet wide and 16 feet high, that spans the lanes of the highway, Gantry Type is BRIDGE. Notice how the description of the feature has changed, the description has been generated from the classification and attribute values.
I’ve duplicated this record and created a similar feature GANTRY-LCD with the Classification GANTRY \ LCD, this has the same attributes, but as you have changed the classification you will need to re-enter the ALN and Numeric values.
In the Classifications application the top of the classification is the same for linear as it is for non-linear classifications. We are looking at the GUARDRAIL classification which is used with the FEATURES object.
In the Attributes table window and if you open the table details there is the addition of two fields when Linear is licensed.
- Linear Type (LINEARTYPE) – this has a supporting ALN Domain (FEATURETYPE) with values for POINT or LINEAR. With POINT the start and end measure must be the same, for LINEAR the start and end measure must be different. If you leave the field null, the attribute will not be displayed on a linear asset.
- Continuous (CONTINUOUS) – A continuous attribute spans the length of the linear asset, or it spans the length of the linear asset when used in conjunction with other attributes without overlapping. When unchecked the linear attribute spans a segment of the linear asset.
Note. I’ll be reviewing these settings more as part of the article Linear Assets (4) – Asset Specifications.
There is an existing Classification called LANE – Road Lane, which has three attributes LANEUSE, REVERSE and WIDTH. I am going to add three additional attributes.
There are two hidden fields on an attribute that can be used with a linear asset, the Linked To Attribute and Linked to Section. These fields are used when an attribute supports another attribute. For example, a Road Surface feature may be supported by material type, subgrade and thickness attributes, I’ve added MATERIAL, SUBGRADE and THICKNESS to the classification under a Section called ROADSURF.
In this case the thickness attribute is referencing the subgrade and not the material type. The two fields Linked To Section and Linked To Attribute can be used to make a connection explicit. You can only link to attributes in the same specification. For the MATERIAL attribute I have set the Linked to Section to ROADSURF and the Linked To Attribute to SUBGRADE. There are no domain lookups by default, and you will find it easier if you are going to use these fields to create a couple of table domains, one for each field.
Incidentally, a Section reference in a Classification’s Specification is used to group attributes. The same attribute name can exist multiple times in the same classification, but it must exist in different sections. The LINKEDTOATTRIBUTE and LINKEDTOSECTION attributes exist in all xxxSPEC objects. You will probably need to unhide these fields in other applications so that you can check that the values are being copied across and to set the values on existing records.
You might notice that for the new MATERIAL attribute I have set the Linear type to LINEAR and checked the Continuous field. I’ve done the same for the other two attributes SUBGRADE and THICKNESS, and we’ll see how these behave in the article Linear Assets (4) – Asset Specifications.
The field help for the Continuous field reads as “If the check box is cleared (the default), you can apply the attribute to a segment of the linear asset. If selected, the attribute spans the entire length of the associated linear asset. A continuous attribute can be a single attribute with start and end measures that are equal to the start and end measures of the linear asset. Or a continuous attribute can be one of multiple attributes that together span the entire linear asset without overlapping. To verify whether the attribute can be continuous, run the Linear Gap and Overlap report.”.
It is the bit which says, “Or a continuous attribute can be one of multiple attributes that together span the entire linear asset without overlapping”, which I will explore in another article.