Improving Security Frameworks (ISF) Frequently Asked Questions

Improving Security Frameworks is a reform initiative in the National Electricity Market. The initiative was finalised by AEMC on March 28, 2024, and is currently implemented by AEMO in collaboration with industry as part of the NEM Reform Program suite of initiatives.

The reform includes:

1. alignment of the existing inertia and system strength frameworks (introducing a NEM-wide inertia floor, aligning procurement timeframes with the system strength framework, and removing restrictions on the procurement of synthetic inertia);
2. removal of the exclusion to procuring inertia network services and system strength in the NSCAS framework;
3. creation of a new transitional non-market ancillary services (NMAS) framework for AEMO to procure security services necessary for the energy transition;
4. requirement for AEMO to enable (or ‘schedule’) security services across the whole NEM for a variety of service types; and
5. changing the directions reporting framework.

Refer to ISF Final rule, clause 4.4A.2 which defines system security services as:

1. a system strength service;
2. an inertia network service;
3. a NSCAS; and
4. a transitional service,

to the extent procured by AEMO or a Transmission Network Service Provider under an agreement for that service under the Rules.

Further detail is provided in the AEMC’s final determination, p86 Table 6.1, which sets out which system security services are included in AEMO’s enablement process.

An increasingly variable generation mix is making power system security more challenging to manage. Building on existing frameworks within the power system, the key benefits of ISF are:

• empowering the market operator to schedule system security services, reducing market interventions
• incentives for industry to invest in capability allowing for the provision of system security services
• improved transparency for consumers and industry on system security needs, providing assurance how power system security needs will continue to be met through the transition
• building knowledgebase around methods to manage security in a changing energy system.

The rule commencement date including full enablement obligations on AEMO is 2 December 2025.

There are multiple milestones in the lead up to this date – please refer to the latest AEMO High Level Implementation Assessment (HLIA) for a summary of these, found on the ISF project page at AEMO’s website. Affected participants are encouraged to join the NEM Reform Program forums to stay up to date, and collaborate with AEMO and industry on, the implementation and preparation for commencement of ISF.

To assist affected parties prepare for the ISF changes, AEMO has published a draft High Level Implementation Assessment (HLIA) that provides details of key impacts to procedures, AEMO systems and processes along with the proposed timeline, implementation approach and initial industry readiness approach.

The industry readiness approach will form the basis of activities to be monitored and reported to stakeholders via the NEM Reform Program Consultative Forum and Implementation Forum. The approach defines the readiness parameters for both industry and AEMO against which the decision to ‘go-live’ will be made. It also defines the agreed approach to support industry testing and the test environments appropriate to support this process.

AEMO can assist stakeholders with their implementations through forums, focus groups, and provision of technical specifications, guidelines and FAQs. Stakeholder enquiries are also answered via the NEM Reform mailbox. Affected parties are encouraged to participate in a market trial to be facilitated by AEMO over a 2-month period, from 1 October 2025. AEMO will develop a Market Trial Strategy and Test Plan in collaboration with participants and publish on AEMO’s website.

AEMO will collaborate with industry to determine deployment activities for go-live and if any transitional, accreditation or registration activities are required, details for which will be published on AEMO’s website for the ISF initiative.

The system strength framework set out obligations for AEMO and the TNSPs related to planning and procuring system strength services ahead of the operational timeframe.

The ISF Rule defines the operational scheduling (or enablement) of system security services as an AEMO responsibility from 2 December 2025. These services may include those procured for system strength under the System Strength framework.

TNSPs each follow a RIT-T process for investment in system strength, including non-network options procured via power system security contracts. Please refer to individual TNSPs for more information on their procurement processes e.g.

The context of the power system security services being enabled by AEMO’s new scheduling function anticipates unique contributions from providers to address security gaps, specific to technical characteristics and locations. It is unlikely that these services can be commoditised and provided from assets distributed amongst a broad portfolio.

AEMO’s scheduling function would take inputs for each individual asset that is under contract to provide system strength services. This will include a ‘dynamic’ input for availability of each of these individual assets, so that availability in the operational timeframe can be considered when determining the security schedule.

AEMO will also set out, via the Security Enablement Procedure, a set of cost inputs that must be provided to AEMO on a per-unit basis to ensure consistency of inputs across all security contracts and therefore allow AEMO to set a least-cost schedule.

Directions would be a last resort if insufficient system security services are available for scheduling.

A milestone under the ISF rule relating to improving directions transparency was implemented from 4 July 2024, involving increased reporting mandate on market notices. For more information, refer to the Procedures for issue of directions and clause 4.8.9 instructions.

Under the ISF Rule, AEMO is prevented from enabling a contract for security purposes more than 12 hours ahead of the trading interval. There is a principle of enabling a service as close to real time as practicable in the ISF Rule and final determination. In practical terms, this means AEMO will not be giving a binding request that an asset is activated from a non-operational state more than 12 hours ahead of the identified security gap. In its scheduling inputs, AEMO will consider an Activation Lead Time for each asset. AEMO will consider an asset unavailable for scheduling if the Activation Lead Time is more than 12 hours. For more information, refer to the Provisional Security Enablement Procedure.

In the operational timeframe, AEMO will provide a mechanism for providers to submit their availability expectations. This will enable AEMO to ensure any units unavailable for service provision are not scheduled.

1. It is anticipated that services generally will be required for durations typically extending multiple hours. “An asset must be capable of continuous service provision for at least 2 hours” is a requirement set by AEMO to make it practicable for AEMO to schedule contracts if they can provide their services for some time. If this requirement was not set, AEMO could encounter complexity/unworkability with having to schedule many short contracts in succession to cover a system security gap of typical duration. Note the unit doesn’t necessarily have to provide the service for more than 2 hours if it is not asked to do so.
2. “There is no minimum or maximum period for which services can be enabled, subject to the notified Availability and Activation Lead Time”, affords AEMO the flexibility to meet system security gaps of varying duration. If the gap only occurs for a short period of time, AEMO can enable assets to meet the gap without unnecessary excess enablement, as required under 4.4A.4 of the rule. If the gap is long (e.g. 12 hours), AEMO can enable an asset for that length subject to their availability/activation lead time.

AEMO is not intending to restrict a units mode as an ISF requirement, provided they can guarantee the service will be delivered continuously while in that mode. The ISF scheduling decision will be made based on operating in a certain mode, based on the cost parameters in the contract associated with operating in that mode. In terms of the generator’s contract, the potential for different operating modes is contemplated in section 2.1 of the Provisional Security Enablement Procedure.

AEMO has adopted a phased approach to delivering the ISF project in order to balance a tight delivery timeframe for meeting full enablement obligations by 2 December 2025. AEMO will deliver a scheduling solution that is fit for purpose by 2 December 2025, considered as phase 1.

Phase 2 scope is likely to generally consist of internal AEMO efficiency/automation changes whilst endeavouring to minimise any participant-side changes during this phase. AEMO is currently in detailed planning and mobilisation for the project.

Providers are the parties that enter into system security contracts with the procurer - AEMO or TNSPs - to provide the services impacted or introduced by ISF. These providers will be identified via AEMO and TNSPs’ respective procurement processes for these services. Please refer to Section 5 – Participant Impacts of the ISF HLIA for further context:

Yes. More details around this can be found in v2 of the HLIA. Preliminary information is available in our provisional security enablement procedure. The latest version of these documents can be found on the ISF project webpage.

AEMO endeavours to use existing portals/interfaces where possible for issuing these instructions. More details around the form and interface are planned to be provided in v0.3 of the HLIA which is due to be published in March 2025.

There are next day reporting obligations as part of the ISF rule to provide transparency. Providers will be required to submit bids/offers into the energy market in response to enablement instructions.

These visibility arrangements are different to that for directions transparency.