Case studies / Energy and Utilities
Case studyMaintenance planning for an electricity distribution network
A New Zealand electricity distributor replaced paper work orders with planned maintenance on mobile devices, reviewed critical spares by criticality and avoided long outages.
Overview
A community-trust-owned electricity distribution business serving a largely rural region of New Zealand's North Island, with a mix of overhead lines, underground cable, zone substations and a small hydro scheme.
Scale. About 110,000 connections, 9,000 kilometres of lines, 28 zone substations, around 60,000 poles and 300 field staff and contractors working from 5 depots, delivered as a phased, multi-location programme.
The challenge
Work orders were paper-based. A planner printed job packs, crews took them into the field, and completed sheets came back days or weeks later, sometimes soaked, sometimes not at all. Pole inspection results, defects found and parts used were keyed into the asset system in batches by office staff, if they were keyed in at all.
Maintenance was mostly reactive. Storms brought down lines and the network responded, which it did well. Planned work such as pole replacement, vegetation management and substation servicing was scheduled from an asset register that many in the field knew to be inaccurate, so crews often found the wrong pole type or a transformer that had already been replaced.
Critical spares were held according to habit. Each depot kept its own stock of cross-arms, insulators and cable, and some items were held in large quantities while others, such as spare power transformers and specific switchgear, had only one unit in the whole network or none at all. When a zone substation transformer failed, the lead time for a replacement could be many months.
Regulatory reporting on reliability and asset condition took the asset management team weeks each year, reconciling paper records with outage logs and financial data.
The solution
Work orders now go to crews on rugged tablets, with the asset, its history, safety information and the job steps. Crews record inspection results, defects, photographs and parts used on site, offline if necessary, and the asset register updates when the device reconnects. Defects found during inspection become follow-up work orders automatically, prioritised by risk.
Planned maintenance is scheduled by asset class: pole inspections on a fixed cycle, vegetation work by corridor and growth rate, substation servicing by equipment type and condition. Planners can see crew capacity across depots and bundle nearby jobs to reduce travel on long rural routes.
Critical spares are held according to their criticality. Items whose failure would cause long outages and that take months to replace are held centrally with agreed minimum quantities, and arrangements are in place with neighbouring networks to share some large items. Routine stock is pooled across depots. Shared master data for assets, locations and parts feeds management dashboards and regulatory disclosures directly.
The engagement
- Nine months
- Six specialists, with asset management, field operations, stores and regulatory leads
- Process mapping, mobile work orders, planned maintenance by asset class, critical spares by criticality, regulatory reporting, shared master data, pilot and phased rollout.
Integrations
- Asset register and document systems
- Outage management and payment services
- Field and mobile applications
- Management dashboards
How we delivered it
- 01
Map the work with the people who do it
Seven weeks
We rode with line crews, sat with planners and dispatchers at each depot, walked substations with technicians and spent time in the stores. With the chief executive and asset manager we agreed the scope: mobile work orders, planned maintenance, critical spares and regulatory reporting.
- 02
Design common processes and integrations
Thirteen weeks
Line mechanics and technicians designed the mobile forms themselves, keeping them short enough to complete on a pole in the rain. Asset engineers set maintenance strategies by asset class. Stores and engineering ranked every spare by consequence of failure and replacement lead time.
- 03
Pilot in one depot
Eight weeks
The largest depot piloted the processes. The pilot found areas with no mobile coverage and poles recorded in the wrong location. Offline working was added, and crews corrected asset locations as part of normal jobs.
- 04
Roll out in waves and track results
Twelve weeks
The remaining four depots followed in two waves. Leadership reviewed planned versus reactive work, spares cover and reporting effort monthly.
Results
- Planned maintenance rose
- Work orders recorded on site, not on paper
- Critical spares held by consequence of failure
- Teams worked from the same data across five depots
Planned maintenance rose as a share of all work. Crews spend more time preventing faults and less time responding to them, and the asset register is now accurate enough for planners to trust.
Reviewing spares by criticality avoided long outages. When a zone substation transformer failed during a winter storm the following year, a spare was already on site in the central store and supply was restored in days rather than months. The review also released surplus routine stock held at several depots.
Regulatory reporting draws on the same data the crews record, so preparation takes a fraction of the effort. Teams at all five depots work from the same data, and leadership reviews results monthly.
The crews built the forms, so they use them. And the day the transformer went, having the spare in the shed was worth the whole programme.
What made the difference
The operator reviewed spares by criticality and avoided long outages. Involving the people who do the work early made adoption easier: line crews designed the mobile forms they now complete on the pole.
