MP092 'New Planned Maintenance methodology'

In April 2019 the DCC began a trial of a new approach regarding the delivery of Planned Maintenance. The new approach sought to categorise planned changes as either low or high impact, based upon a risk-based methodology. It also amended the timings with which Planned Maintenance was scheduled and implemented.
Whilst the SEC is silent on the methodology for scoping Planned Maintenance, it does set out when the Maintenance should occur and the timescales around publishing Maintenance schedules (Sections H8.3 and H8.4). In order to trial the new approach, the SEC Panel granted the DCC a derogation against these provisions for six months (later extending for a further three months until February 2020). The Panel requested the DCC report on progress to the Operations Group.

In July, the DCC reported the trial had been a success and, following a final report to the Operations Group, intended to raise a Modification Proposal to formalise the new approach.

The DCC is proposing implementing the new methodology on an enduring basis, to allow more low impact changes to be implemented more of the time and allow more focus on fewer high impact changes.

The solution aims to improve visibility of changes to SEC Parties, improve quality of changes deployed, improve alignment to demand and focus on business impact rather than solely focusing on the amount of downtime. This requires update to the SEC to create the concept of High and Low Impact Maintenance windows and detailing the outage duration associated with each.