Glossary

Overview

This glossary defines key terms used throughout the Practice Guide. Where a term is drawn from or consistent with the IIMM, GIMM, ISO 55000, IPSASB or IPSAS 51, the source is noted. Terms marked ‘PG’ are defined specifically for this Practice Guide.

Use this Resource page to check common asset-management, green-infrastructure and service-potential terms used across the Practice Guide. The definitions are intended to support consistent AMP writing, practitioner discussion and cross-Step interpretation.

Glossary terms

A

Long-term plan (usually 10–20 years for infrastructure assets) that outlines the asset activities and programs for each service area and the resources applied to provide a defined level of service in the most cost-effective way.

A forward-looking, prioritised set of actions to improve asset management practice, data quality, systems and capability so that the next AMP cycle produces a better plan. Typically five to eight prioritised tasks, each traceable to a specific data gap or analytical limitation identified earlier in the AMP. Distinct from the Improvement Log (which records operational lessons during the current cycle). Standard IIMM/NAMS practice; explicit demonstration of AM maturity. Documented in Step 9 of the AMP.

An item, thing or entity that has potential or actual value or benefit to an organisation.

A grouping of assets that share similar attributes, functions, lifecycle characteristics or management requirements. In this Practice Guide, GI asset classes include urban trees, wetlands, raingardens, green roofs, bushland and coastal reserves.

A framework for segmenting an asset base into appropriate classifications. The hierarchy can be based on asset function, asset type, or a combination of the two.

The coordinated activity of an organisation to realise value from assets.

A set of interrelated or interacting elements of an organisation, including the AM policy, AM objectives, AM strategy, AM plans, and the processes to achieve these objectives.

A record of asset information typically held in a spreadsheet, database or software system, including asset attribute data such as quantity, type and construction cost. In this Practice Guide, the register also records ecological and hydrological attributes for green infrastructure.

The conventional IIMM/IPWEA Practice Note 6 indicator measuring actual renewal expenditure as a proportion of required renewal expenditure. The IPWEA benchmark target is ≥ 90%. This Practice Guide does not use ARFR as a primary indicator for green infrastructure because for many GI asset classes (urban trees, bushland, continuously-stewarded assets), renewal is not the primary mechanism for sustaining service potential — ongoing operations and maintenance is. The PG framework uses the adapted GI Sustainability Ratio (see entry), supplemented by the OPEX Coverage Ratio and Lifecycle Cost Gap.

The conventional IIMM/IPWEA Practice Note 6 indicator measuring renewal expenditure as a proportion of depreciation (a proxy for asset consumption). A ratio of 90–110% indicates renewal is keeping pace with consumption. This Practice Guide adapts this concept for green infrastructure as the GI Sustainability Ratio (see entry), which uses total investment (renewal + O&M) rather than renewal alone because for many GI assets, ongoing O&M is the primary mechanism for sustaining service potential.

B

The total annual expenditure (OPEX and CAPEX) required to sustain desired levels of service across the planning horizon, before comparison with available funding in the LTFP.

One of four planning scenarios used throughout Steps 6–9 to test the consequences of different investment levels and management approaches on service potential. BAU continues current budget levels and current practice settings, with no real funding increase and no change in delivery, survival or management practice. The service potential trajectory under BAU depends on the asset class's starting conditions and may show structural decline where current funding is insufficient. See also: Funding-led; Survival-led; Optimised Levers; Service Potential Status.

C

The percentage of a defined area covered by the vertical projection of tree crowns. Used as a key technical LOS indicator for urban tree asset classes.

Expenditure used to create new assets, renew assets, expand or upgrade assets, or to increase the capacity of existing assets beyond their original design capacity or service potential. CAPEX increases the value of asset stock.

An ancillary benefit arising from an asset or intervention beyond its primary function. For green infrastructure, co-benefits may include cooling, carbon sequestration, biodiversity, amenity, mental health and recreation value.

The inspection, assessment, measurement and interpretation of the resultant data, to indicate the condition of a specific component so as to determine the need for some preventive or remedial action.

A measure of the physical integrity of an asset or component. This Practice Guide uses a practical 1–5 scale for first-cycle application, while recognising that some mature organisations may use broader 0–10 or 1–10 scales where data quality, assessor calibration and decision thresholds support that level of precision.

Activities that consolidate outputs from individual AMPs at the organisational level — for example, aggregating lifecycle cost forecasts from multiple asset classes into a single LTFP or corporate asset management report. Distinguished from AMP scope.

Those assets that are likely to result in a more significant financial, environmental and social cost, measured by impact on organisational objectives.

The relative importance of an asset in delivering services or achieving outcomes. In this Practice Guide, criticality for GI considers ecological network function, proximity to vulnerable populations, statutory obligations and risk consequence.

D

The shortfall in maintenance work required to maintain the service potential of an asset.

Actions taken to influence demand for services and assets, often undertaken to avoid or defer required asset investment. In GI contexts, demand management includes urban heat mapping, growth-area canopy planning and developer contribution frameworks.

The systematic allocation of the depreciable amount of an asset over its useful life.

E

The benefits that people and communities derive from ecosystems, including provisioning services (e.g. food, water), regulating services (e.g. flood mitigation, air quality), cultural services (e.g. recreation, wellbeing) and supporting services (e.g. soil formation, nutrient cycling).

F

The amount for which an asset could be exchanged or a liability settled, between knowledgeable, willing parties in an arm’s length transaction.

The capacity of an organisation to continue providing services at the desired level, maintain and renew assets as they age, and do so without transferring unreasonable financial risk to future generations.

One of four planning scenarios used throughout Steps 6–9. Funding-led models an increased funding envelope without significant change in delivery, survival or management practice. Demonstrates the limits of additional funding alone: service uplift is typically modest because non-financial constraints (delivery capacity, survival rates, management practice) remain binding. Diagnostic value lies in testing whether funding is the binding constraint. See also: BAU; Survival-led; Optimised Levers.

G

Published by IPWEA, the Green Infrastructure Management Manual provides guidance for applying asset management principles to green infrastructure assets. It supports the management of living, adaptive and multifunctional assets through service-based planning, lifecycle management, risk, levels of service and long-term financial planning. This Practice Guide draws on GIMM alongside the IIMM and adapts those principles into a nine-step AMP method for local government green infrastructure.

The network of natural, enhanced and engineered assets that deliver critical services to communities and ecosystems. Includes natural systems such as wetlands, forests, rivers and soils, as well as urban features like green roofs, bioswales and permeable pavements designed to mimic natural processes.

A financial sustainability indicator adapted from the IIMM Asset Sustainability Ratio tradition for green infrastructure systems. It compares available investment against required investment needed to sustain agreed service potential and levels of service. Uses total investment (renewal + operations and maintenance) rather than renewal alone, because for many GI assets, ongoing O&M is the primary mechanism for sustaining service potential — not periodic renewal as it is for grey infrastructure. The principal financial sustainability indicator for living assets; complemented at the LTFP level by the OPEX Coverage Ratio and Lifecycle Cost Gap. Target: ≥ 90%. See also: Asset Sustainability Ratio (the IIMM term GI Sustainability Ratio is adapted from); OPEX Coverage Ratio; Lifecycle Cost Gap.

The fictitious local government area used as the consistent worked example throughout this Practice Guide.

Conventional engineered infrastructure systems such as roads, pipes, bridges, buildings and drainage networks. Typically linear, static and depreciating, with performance assessed through physical condition and capacity.

I

The globally recognised reference manual for infrastructure asset management, published by IPWEA. The 6th Edition (2020) provides comprehensive ‘how to’ guidance aligned with ISO 55000.

A register of improvement actions identified through the monitoring, measurement and evaluation process (Step 9). Each entry records the issue, root cause, proposed action, responsible officer and completion status.

Integrated Planning and Reporting Framework. In New South Wales, the statutory framework administered by the Office of Local Government that links community aspirations (Community Strategic Plan) through to resourced delivery (LTFP, Workforce Plan, AMPs).

International Public Sector Accounting Standard 51 — Tangible Natural Resources Held for Conservation. Approved December 2025; effective 1 January 2028. Confirms that tangible natural resources embody service potential or the capability to generate economic benefits, or both.

The international standard for asset management, comprising ISO 55000 (overview, principles and terminology), ISO 55001 (management system requirements) and ISO 55002 (guidelines for the application of ISO 55001).

K

A quantifiable measure used to evaluate the success of an asset, service or activity in meeting defined objectives. In this Practice Guide, KPIs are linked to levels of service targets and reported through governance dashboards.

L

A quantifiable measure of a combination of parameters that reflect social, economic and environmental outcomes that the organisation delivers. This Practice Guide applies a three-dimensional LOS framework: Technical, Community and Resilience.

The organising structure of this Practice Guide. A nine-step asset management planning process divided into three phases (Know Your Assets / Plan the Lifecycle / Secure the Future), with three steps in each phase.

The total cost of an asset throughout its life, including planning, design, construction, acquisition, operation, maintenance, rehabilitation and disposal costs.

The difference between the lifecycle expenditure required to sustain the agreed level of service or service potential and the funding currently available or planned. In this Practice Guide, the gap is used to explain the service, risk and financial consequences of underfunding green infrastructure over time.

A financial plan, typically covering 10 or more years, that models an organisation’s projected revenue, expenditure, assets and liabilities. The LTFP is the funding instrument into which AMP cost forecasts are consolidated.

M

The phenomenon by which a growing proportion of a living asset portfolio reaches cost-intensive maturity stages over time. Causes OPEX to rise gradually as canopy and ecological benefits accelerate. Managed through fractional transition modelling rather than step-change cohort assumptions.

N

An asset derived from or sustained by natural ecological processes. May be naturally occurring (e.g. remnant bushland, wetlands, coastal dunes) or enhanced through management intervention (e.g. revegetated corridors, constructed wetlands).

O

Recurrent expenditure required to provide a service, including the ongoing costs of operating, maintaining and managing assets. For GI, OPEX includes stewardship activities such as watering, mulching, pruning, weed control and ecological monitoring.

Supplementary financial sustainability indicator: funded operational expenditure as a proportion of required operational expenditure. Captures specifically the maintenance dimension that the GI Sustainability Ratio captures jointly with renewal. Particularly important for green infrastructure: GI assets are sensitive to maintenance underfunding, and deferred stewardship can cause rapid, irreversible loss of ecological function and service potential. Target: ≥ 90%. See also: GI Sustainability Ratio; Lifecycle Cost Gap.

One of four planning scenarios used throughout Steps 6–9. Optimised Levers models coordinated improvement across funding, survival, delivery and management practice as a staged multi-year investment. Typically delivers the strongest service potential outcomes and reduced long-term renewal liability. The recommended scenario where multiple constraints interact; typically the case carried into Step 8 as the LTFP request. See also: BAU; Funding-led; Survival-led.

R

The time remaining until an asset ceases to provide the required service level or economic usefulness.

Works to replace existing assets or facilities with assets or facilities of equivalent capacity or performance capability.

The capacity of public, private and civic sectors to withstand disruption, absorb disturbance, act effectively in a crisis, adapt to changing conditions including climate change, and grow over time. Applied in this Practice Guide as the third dimension of levels of service.

The effect of uncertainty on objectives, evaluated by considering the likelihood and consequence of a situation or event.

A documented record of identified risks, their likelihood, consequence, current controls and planned treatments. In Step 6, the risk register links to service potential outcomes and financial implications.

S

IPSASB definition: The capability of a resource to provide services that contribute to achieving the entity’s objectives. Service potential enables an entity to achieve its objectives without necessarily generating net cash inflows.

Practice Guide use: For green infrastructure asset management, Service Potential means the ability of a living, adaptive or multifunctional asset to continue delivering its intended community, environmental, resilience and economic services over time. This Practice Guide applies the concept through remaining service potential, desired service potential, service potential at risk and restoring service potential.

Step 9 monitoring indicator: the current weighted-average service potential index divided by the as-new service potential index. Measures the proportion of service potential currently retained relative to as-new state. A current-state monitoring output, distinct from the Service Potential Status (a forward-looking scenario-trajectory output from Step 6 modelling). Where no condition data exists, the funding-adequacy proxy of the companion spreadsheet provides a reasonable starting point; the condition-based measure should progressively replace the proxy as monitoring data improves through successive AMP cycles. See also: Service Potential Status; Service Potential.

A strategic indicator describing the projected trajectory of service potential under a tested scenario. Output of Step 6 scenario modelling (the LFA Green Infrastructure Modelling Framework). Status classifications: Structural decline; Partial stabilisation; Improving; Strong uplift trajectory. Supported by a numeric Score (0–1) measuring realised service potential against achievable best under the scenario's lever settings. Distinct from Service Potential Retained (a current-state monitoring output from Step 9). See also: Service Potential Retained; Service Potential; BAU; Funding-led; Survival-led; Optimised Levers.

The ongoing, proactive care and management activities required to sustain green infrastructure through its lifecycle. Includes establishment care, routine maintenance, ecological monitoring and adaptive intervention. Distinguished from reactive maintenance in that stewardship is planned and preventive.

The difference between the current or projected supply of a GI service (e.g. canopy cover, WSUD treatment area) and the target level established through levels of service and demand analysis.

One of four planning scenarios used throughout Steps 6–9. Survival-led combines a modest funding uplift with practice changes that improve establishment success, retention and management — typically the most cost-effective scenario where practice change is achievable. Better survival reduces future renewal demand, lifting service potential without the funding step required by Optimised Levers. See also: BAU; Funding-led; Optimised Levers.

U

The period over which an asset or component is expected to be available for use by an entity.

W

An approach to urban planning and design that integrates the urban water cycle into the built environment. WSUD is a design approach, not an asset class. In this Guide the assets it produces are recorded under Green stormwater infrastructure / WSUD, which covers the vegetated (nature-based) measures: bioretention systems and raingardens, constructed treatment wetlands, vegetated swales and buffer strips, stormwater detention basins, tree pits and infiltration systems. Non-vegetated measures such as rainwater tanks, permeable paving and pit inserts support these assets but are grey infrastructure and sit outside the Guide’s scope. Equivalent terms are used elsewhere: green stormwater infrastructure (GSI) and low impact development (LID) in North America, and sustainable drainage systems (SuDS) in the United Kingdom. Constructed treatment wetlands are recorded in this class because they are built assets — designed, acquired and ultimately decommissioned; natural and naturalised wetlands are recorded under Waterways, wetlands and riparian systems.

Terminology conversion

Scroll right to view the full terminology conversion table →

Source key