Linear Assets Terminology

attribute

A property of a linear asset or feature, sometimes referred to as a specification.

For example, speed limit is an attribute of a highway (a linear asset), with multiple possible values (40 mph, 50 mph, and so forth). Guardrail (a feature) comes in different types. You can define "Type" to be a guardrail attribute, and then specify different values for the different types.

You can apply an attribute to an entire linear asset or just part of it. For example, a 50 mph speed limit might apply to all or part of Route 96.

dynamic segmentation

The ability to analyze a linear asset multiple ways without affecting its underlying geometry.

For example, you define a road as a linear asset. It starts at mile 0 and ends at mile 60. You assign a speed limit of 55 mph to miles 0 to 20, and a speed limit of 65 mph to miles 20 to 60. At the same time, the number of lanes might be 3 from miles 0 to 40, and 4 from miles 40 to 60.

You do not split the linear asset into multiple assets to accommodate the changing properties. You define the properties in the context of the one linear asset. You segment the linear asset virtually to analyze it and work with it.

feature

A physical object that you associate with a linear asset, but which itself is not an asset. You typically use features (for example, mile posts) to locate where work will take place. You create feature records in the Features application.

You can associate one or more feature instances with a linear asset. You apply costs associated with a feature instance against the linear asset where the feature instance occurs. For example, you create a feature called Mile Post, and you create a feature instance labeled MP 27 on Route 95. If you repair MP 27, the cost for the repair is charged to Route 95.

The use of features will vary based upon your business model. If you want to track costs against an object, create an asset record for it, not a feature record.

You can also create features by using the relationships that you define in the Relationships application. For example, a municipality often uses intersections to locate work. By relating two streets and specifying that the relationship is a reference point, a feature instance is automatically created each time the relationship is applied to linear assets.

feature instance

A feature that you have associated with a linear asset. For example, you create a feature, mile post. When you associate it with a particular linear asset, in a particular location, it is a feature instance.

linear asset

An asset whose length plays a critical role in its maintenance, for example, roads, railways, trails, and pipelines. Its length, and measured points along its length, are integral to how you track and define a linear asset's properties.

linear referencing

Defining the location of a point along a linear asset.

Linear referencing in the IBM Maximo Linear Asset Manager uses distance measures from known points along X, Y, and Z axes. The X axis is the length of the linear asset. The Y axis is a distance to the right or left of the linear asset. The Z axis is a distance above or below the linear asset.

linear referencing method

A method of determining a position by using a known start point, a measure, a direction, and offset values. To define a linear referencing method, you specify units of measure for the length of the linear asset and for three offset measures (see offset, below). You can define multiple linear referencing methods.

linear segment

A span of a linear asset defined by a start and an end measure. The span can be the entire length of the linear asset or any continuous part of it.

The start and end measures for the linear segment must be within the start and end measures of the linear asset. A linear segment cannot overlap two linear assets.

measure

The absolute distance from the start of a linear asset.

You can enter a measure manually, or, if you enter a reference point and reference point offset, the measure is calculated automatically.  

offset

A measure from a previously defined reference point. There are three kinds of offsets:

• Reference Point Offset (also known as X offset, or simply "offset"). A distance along the length of the asset measured from a previously defined reference point. For example, a speed sign is .2 miles from milepost 10.

• Y-Offset. A distance perpendicular to the direction of the linear asset. For example, a speed limit sign is located 10 feet from the right edge of the road. "Right" is positive and "left" is negative. Therefore, the Y offset is 10.

• Z-Offset  -  a distance above or below a linear asset. For example, an exit sign is located 18 feet above the surface of the road, and a culvert is 4 feet below the surface of the road. The Z offset for the sign is 18, and the Z Offset for the culvert is -4.

point asset

An asset whose length does not play a critical role in its maintenance, for example, a pump, railway switch, or camera. With a point asset, you do not assign work to a particular length of the asset, but rather to the entire asset or to its parts.

reference point

A feature instance that you can use as a start or end point for a linear segment.

A reference point is a means of communicating a work location. For example, it can be more useful to workers to say that roadside mowing on Route 96 begins at the intersection of Routes 96 and 75 and ends at exit 34, than to say the work begins at mile 27.85 and ends at mile 33.8.

The use of reference points will vary according to department practices and individual variation among linear assets. Some roads might have accurate and persistent mile post markers and workers can rely on them to locate work. Other roads might have few or no accurate markers, and users will rely on reference points.

relationship

A defined interdependency between two linear assets, a linear and a point asset, or a linear asset and a location. You define relationships in the Relationships application. Relationships can be physical (for example, "intersects with," "is parallel to") or abstract (for example, "belongs to," "is owned by").