IT Release Schedule

Details of proposed changes to IESO systems and reports being revised for the current release are available here. Each release includes a preliminary, target and final plan—posted according to the IT Release Schedule. A yellow box indicates that the plan is not published for this release.

Preliminary Release Plan

Target Release Plan

Final Release Plan

Release ID

  R48.1 R49.0 R49.1 R50.0 R50.1
Release Category Category 2 Category 3
(incl.Cat 2)		 Category 2 Category 3
(incl.Cat 2)		 Category 2
Real Time Production Build 7 Dec 2022 1 Mar 2023 7 Jun 2023 13 Sep 2023 6 Dec 2023
1. Preliminary Release Plan
Prepared 		24 Aug 2022 16 Nov 2022 22 Feb 2023 31 May 2023 23 Aug 2023
2. Market Participant Feedback
Period Ends
 7 Sep 2022 30 Nov 2022 8 Mar 2023 14 Jun 2023 6 Sep 2023
3. Target Release Plan 21 Sep 2022 14 Dec 2022 22 Mar 2023 28 Jun 2023 20 Sep 2023
4. Final Release Plan 19 Oct 2022 11 Jan 2023 19 Apr 2023 26 Jul 2023 18 Oct 2023
5. Sandbox Implementation 27 Oct 2022 19 Jan 2023 27 Apr 2023 3 Aug 2023 26 Aug 2023
6(a). Production Build
(Non Real Time) 		30 Nov 2022 22 Feb 2023 31 May 2023 6 Sep 2023 29 Nov 2023
6(b). Production Build
(Real Time) 		7 Dec 2022 1 Mar 2023 7 Jun 2023 13 Sep 2023 6 Dec 2023

Four times per year, the IESO schedules a Preliminary Release Plan detailing upcoming changes to IESO systems that have been assessed to have an impact on participants. Comments on IT changes in the plan can be sent to pending.changes@ieso.ca. Each release includes a preliminary, target and final plan, categorized as the following:

  • Category 3 releases (occurring twice a year) require market participants to make changes to their own technical interfaces with the IESO. Normally, significant system changes are the subject of stakeholder consultation well in advance of this release process.
  • Category 2 releases (occurring four times a year) require market participants to make a change in procedure or to update documentation, but not to modify any IT systems.
  • Category 1 releases do not have any impact on market participants and are managed through the IESO's internal release process. Market participants are notified only of any applicable outages, via the Planned IT Outages webpage.

Updates to the Preliminary Plan are added to the Target Release Plan, which is also open for comment by participants. New items are added to the Target Release Plan if required, and are posted through the IT Release Schedule.

The Final Release Plan is published one week in advance of the Sandbox implementation date, when changes are made available in the Sandbox environment for testing and training. Participants can contact IESO Customer Relations for more information if Sandbox access is required.

After the testing period is complete, the IESO will release the changes in Production, as shown on the IT Release Schedule. Accompanying documentation for the changes is available on Pending Changes – Documents as part of the baseline process.