Electricity Asset Management Plan 2019-2029
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Vector Limited://
CONDITION BASED ASSET RISK MANAGEMENT (CBARM)
NEEDS STATEMENT An asset health indicator is a measure that represents an asset’s stage within its overall life cycle. Asset age has traditionally been used for this purpose and while useful for evaluating population level strategies in circumstances where reliable statistics are available, use of age alone can produce misleading conclusions. In addition to that we rely on asset condition as identified by routine maintenance inspections and replacement undertaken as required based on the identification of risks under the corrective maintenance programme. Asset health is a measure of the condition of an asset and the proximity to the end of its useful life. As the health of an asset deteriorates the likelihood that it will fail due to condition increases. Presently our process to determine the risk and associated weighting for prioritisation of works is rather ad-hoc. To this end Vector is developing CBARM models for its major asset classes to inform our replacement and refurbishment programmes of work and strategies. The key outputs from the CBARM models are evaluation of the probability of failure and the consequence of failure. This will provide a current health score as well as a future health score which is capped at 10 – the higher the score the poorer the asset health and the higher the probability of failure. Any asset with a score higher than 8 requires replacement as soon as possible. The models will enable us to plan and forecast programmes of work to be undertaken on the assets with planning horizons of 1 to 2 year schedules and 2 to 5 year options. The CBARM models provide a bottom up risk priorities plan which allows assessment of investments on a common basis and tests decisions of deferrals as well as expediting work on a risk versus cost basis. Our CBARM models for OH 11 kV conductors, 11 kV ring main units and distribution transformers are mature and we plan to complete CBARM models for other major asset, e.g. power transformers, subtransmission switchgear, poles and crossarms, 11 kV cables, and subtransmission cables – a total of 12 CBARM models will be developed. As we move forward in time our CBARM models will be extended to other smaller asset classes e.g. protection relays, RTUs, PQM meters, and the like.
TARGETED OUTCOMES
CUSTOMER EXPERIENCE
SAFETY
RELIABILITY
RESILIENCE
OPERATIONAL EFFICIENCY
CYBER SECURITY AND PRIVACY
OPTIONS CONSIDERED Options to address the need identified above have been assessed and are summarised in the following table.
DESCRIPTION
DISCUSSION OF OPTION
ESTIMATED COST (NPV IF APPLICABLE)
STATUS
Option 1: Do not undertake this initiative – Do nothing
Without CBARM models our decision making will remain ad-hoc and inefficient. Deteriorating asset condition invariably leads to deteriorating network performance and increases safety risk and an ad-hoc approach will simply not achieve the efficiencies to manage ageing asset populations. Condition rather than age will allow better decision making to plan replacements and refurbishment programmes of work. Being informed in a structured way about the condition of asset classes is essential to address issue with escalating failure rates and poor SAIDI and SAIFI performance.
Rejected
Option 2: Implement condition based asset risk models for all major asset classes
$0.50M Selected
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