It is important to establish key terms that are used throughout the Guide. While many of these terms have multiple or nuanced definitions, the definitions listed here are the assumed meanings used in the context of this Guide. Each chapter also lists important terms that expand on this list.
Transportation asset management (TAM) is defined by AASHTO as a strategic and systematic process of operating, maintaining, upgrading, and expanding physical assets effectively throughout their life cycle. It focuses on business and engineering practices for resource allocation and utilization, with the objective of better decision making based upon quality information and well defined objectives.
FHWA defines TAM similarly, stating, “Asset management is a strategic and systematic process of operating, maintaining, and improving physical assets, with a focus on engineering and economic analysis based upon quality information, to identify a structured sequence of maintenance, preservation, repair, rehabilitation, and replacement actions that will achieve and sustain a desired state of good repair (SOGR) over the lifecycle of the assets at minimum practicable cost.”
In the International Standards Organization (ISO) Standard 55000, asset management is defined as the “coordinated activity of an organization to realize value from assets. Realization of value involves the balancing of costs, risks, opportunities and performance benefits.” In addition, the ISO standard states that, “Asset management enables an organization to examine the need for, and performance of, assets and asset systems at different levels. Additionally, it enables the application of analytical approaches towards managing an asset over the different stages of its life cycle (which can start with the conception of the need for the asset, through to its disposal, and includes the managing of any potential post disposal liabilities).”
Performance measures are quantifiable metrics that are used to track progress toward goals, objectives, and established performance targets.
A performance target is a level of performance desired to be achieved within a specific time frame.
State of good repair (SGR) refers to a condition in which existing physical assets, both individually and as a system, are functioning as designed within their useful service life and are kept functional through regular maintenance and replacement programs.
Levels of service are an agency’s stated commitment to deliver asset service at a specified level of quality and reliability. Service levels can be asset performance-related or customer/regulatory-related (complaints, meeting regulatory requirements). These levels of service can include, but are not limited to, the historic “level of service” used to grade traffic congestion.
Asset condition refers to an asset’s current state, as specifically defined by its appearance, perceived level of service, and observed physical state, whether or not it impacts its performance.
Risk is the positive or negative effect of uncertainty or variability upon agency objectives. [23 USC 515.6]
Life cycle planning and management is a process to estimate the cost of managing an asset class, or asset sub-group over its whole life with consideration for minimizing cost while preserving or improving asset condition. [23 CFR 515.5]
Whole-life costing is the systematic consideration of all relevant costs and revenues associated with the development, operations, and maintenance of the asset.
Reliability-centered maintenance is a structured, risk-based approach for determining the maintenance requirement for any physical asset, based on its operating context within the agency.
Resource allocation is the process of assigning scarce resources to investments in transportation assets. The assigned resources can be money, staff time, contractor capacity, equipment, or other organizational requirements for assets. The investments can be capital projects, maintenance efforts, or other projects and activities that require the use of an organization’s resources through various delivery methods.