Determine What Data Is Needed to Support Life Cycle Management
Once a maintenance strategy for an asset class or subclass (e.g. condition-based, interval-based or reactive) is selected, data is required to support the types of decisions needed to manage the asset. The type of data collected will vary based on the selected strategy and the specific decisions needed to be made to manage the asset class. The objective is to make informed, data-driven decisions on the appropriateness, timing and priority of treatment options over the service lives of specific assets. These decisions are supported by field collection of inventory and condition data, as well as the development of higher-level measures and analysis results from that data. The following sections describe methods for determining what data is essential or desirable to support maintenance decisions and the delivery of work.
Regardless of the life cycle approach selected (e.g. condition-based, interval-based or reactive), data is required to support the types of decisions needed to manage the asset. The type of data collected will vary based on the selected approach and the asset class or sub group. As described in this chapter, data is needed to support decision making about the type and timing of actions that can be taken to delay or address asset deterioration, damage, premature failure, or other performance decline. In some cases, the data can directly trigger decisions, such as accident data informing a process to repair or replace guard rail. In other cases, the data is used to support analyses that inform decision making processes, such as condition-based management.
While supporting investment decisions may be the primary purpose for collecting and managing asset data, agencies may have other purposes, such as internal or external reporting, or mandates. Agencies need to make hard choices about what data is essential to support business practices, and what data is merely desirable. Once that is determined the agency must next evaluate the benefit derived from the desirable data along with the cost and benefit of collecting and managing that data. This How-To Guide provides a simple 3-step approach to identifying and evaluating essential and desirable asset data, to determine which data should be collected to support life cycle management. This approach is based on material from the FHWA document, Handbook for Including Ancillary Asses in Transportation Asset Management Programs, which is pending publication in 2019. The Handbook provides additional detail and several examples of data elements typically collected to support life cycle management of different assets. Additional details on data collection and management can also be found in chapter 7 of this guide.
Determine the Essential Data to Support the Maintenance Strategy
While the management approaches discussed in this chapter vary in their degree of complexity, all three require some essential data, which can be categorized into asset class and subclass information, unique identifier information, individual asset location information and action trigger(s). The following sections describe how to determine the best means of addressing each of these data elements.
Asset Class and Subclass
Asset class and subclass are defined by specific attributes that can group individual assets into sets with common management options. Asset classes and subclasses should only be defined to the level of detail that supports treatment selection, prioritization, or delivery. For example, within the asset class ‘guardrail’, it may be advantageous to identify subclasses of ‘box beam’, ‘W beam’ and ‘PCC barrier’. However, there is likely no benefit to further dividing box beam guiderails into subclasses based on the post type or spacing.
For each asset managed using a condition-based approach, a unique identifier is required to link inventory and condition information to the specific asset in the field so it can be evaluated for work as an independent unit. This can become difficult for assets that are components of a system, such as closed drainage systems or roadside sign arrays. In these cases, there may be a need for a parent-child relationship between different asset classes. In the case of sign arrays, the support structure and each sign panel attached to it may be considered individual assets. It is good practice to have a universal system for developing unique identifiers that avoids duplicate identifiers between asset classes.
Individual Asset Location
There are many ways of determining and documenting asset location, including coordinates, linear referencing, street addresses, stationing from physical benchmarks and others. Ideally, an agency has one common referencing approach to use for all assets.
The selected RCM strategy will determine the type of data needed to support action triggers:
- Condition-based strategies require some measure of condition relating to both the performance of the asset and the applicability of potential treatment options. For some assets, such as culverts or drainage structures, this will require multiple data elements to describe aspects of the different means of deterioration or failure, for example sediment or structural deterioration. For other assets, such as sign panels, there may only be one measure of condition, such as retroreflectivity.
- Interval-based strategies require an age element. This could be stored as an installation date or date since last treatment. In the case of the latter, additional data elements to may be needed to describe the treatment. If this information is not known, estimates can be used at early levels of maturity. For example, if signs are generally replaced every 10 years, an agency may assume 10 percent of the inventory needs to be replaced each year.
- Reactive strategies require a means of identifying if and when an event has occurred that requires a response. Examples include identification by field staff or information from accident reports identifying damage or failure.
Determine Desired Data to Support the Maintenance Strategy
Data collection, storage and maintenance is expensive. It is important each data element collected has a clear purpose and use in development or delivery of work plans and projects. The following is a partial list of purposes for collecting data:
- Provide additional clarity, accuracy or precision to the essential data collected
- Support different work units within an agency, such as engineering, operations or planning
- Assist in generating maintenance work orders
- Provide additional detail to manage risks
- Provide details on maintenance intervals
- Support project development through integration with other asset data sets
Align Business Processes
Supporting life cycle management requires the collection and management of data to support multiple business processes, including planning, design, construction, maintenance and operations. Each of these processes has data requirements and may have already been collecting some data on the asset to support those processes. It may be necessary to change business processes to use data already being collected or can be collected more efficiently. This process is described in more detail in Chapter 7.