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Sector Participants > Calendars > Planned IT Outages

Planned IT Outages

All planned IT system outages are posted as soon as they are scheduled. Participants can view outage notification details for the same day, as well as outages planned in the future.


Participants can also view information about outages that occurred in the past 60 days by selecting Archive in the table below.

Planned Outages for 23 Oct 2019

Outage Times Systems Description
12:40 - 12:50 EST IESO Portal Report site will be unavailable and publication of public and confidential Reports will be delayed.Loss of access to the IESO Portal will impact the following applications:
  • Transmission Rights Auction (TRA) application will be unavailable
  • All on-line collaboration communities will be unavailable
  • Prudential Manager used to monitor and retrieve prudential information will be unavailable


EMI application used to submit bids, offers, schedules and forecasts will be unavailable. Market participants should confirm their bids and offers once the outage is completed.
12:20 - 12:25 Day-Ahead Optimization System (DAOS) The Eligible Energy Limited Resource Optimization (EELR) run of the Day-Ahead Commitment Process (DACP) DAOS will not occur:
  • EELRs will be unable to resubmit their offers for consideration in the DACP after the initial DAOS run
  • If the initial DAOS run is successful, it will be considered the Schedule of Record
09:40 - 09:55 EST IESO Portal Report site will be unavailable and publication of public and confidential Reports will be delayed.Loss of access to the IESO Portal will impact the following applications:
  • Transmission Rights Auction (TRA) application will be unavailable
  • All on-line collaboration communities will be unavailable
  • Prudential Manager used to monitor and retrieve prudential information will be unavailable


EMI application used to submit bids, offers, schedules and forecasts will be unavailable. Market participants should confirm their bids and offers once the outage is completed.
Automated dispatch instructions sent via Dispatch Service will be unavailable. The IESO will manually dispatch by phone as necessary. The Dispatch Service Web UI users may get disconnected and will need to login and verify connected after the outage.

Future Outages

Outage Times Systems Description
October 24, 2019
11:20 - 13:20 IESO Portal Loss of access to the IESO Portal will impact the following applications:
  • Transmission Rights Auction (TRA) application will be unavailable
  • All on-line collaboration communities will be unavailable
  • Prudential Manager used to monitor and retrieve prudential information will be unavailable


EMI application used to submit bids, offers, schedules and forecasts will be unavailable. Market participants should confirm their bids and offers once the outage is completed.
EMI application used to submit bids, offers, schedules and forecast will be unavailable.EMI API application used to submit bids, offers, schedules and forecast will be unavailable.OCSS Web User Interface will be unavailable for outage submission and retrieval. Automated dispatch instructions sent via Dispatch Service will be unavailable. The IESO will manually dispatch by phone as necessary. The Dispatch Service Web UI users may get disconnected and will need to login and verify connected after the outage.Report site will be unavailable and publication of public and confidential Reports will be delayed.The Eligible Energy Limited Resource Optimization (EELR) run of the Day-Ahead Commitment Process (DACP) DAOS will not occur:
  • EELRs will be unable to resubmit their offers for consideration in the DACP after the initial DAOS run
  • If the initial DAOS run is successful, it will be considered the Schedule of Record
New person registration in the Registration Application will not be available.
October 25, 2019
09:20 - 09:40 EST EMI MIM Web services used to submit bids, offers, schedules and forecast will be unavailable.

MIM IDK used to submit bids, offers, schedules and forecast will be unavailable.
12:20 - 12:40 EST EMI MIM Web services used to submit bids, offers, schedules and forecast will be unavailable.

MIM IDK used to submit bids, offers, schedules and forecast will be unavailable.
11:20 - 12:23 IESO Portal Loss of access to the IESO Portal will impact the following applications:
  • Transmission Rights Auction (TRA) application will be unavailable
  • All on-line collaboration communities will be unavailable
  • Prudential Manager used to monitor and retrieve prudential information will be unavailable


EMI application used to submit bids, offers, schedules and forecasts will be unavailable. Market participants should confirm their bids and offers once the outage is completed.
EMI application used to submit bids, offers, schedules and forecast will be unavailable.EMI API application used to submit bids, offers, schedules and forecast will be unavailable.OCSS Web User Interface will be unavailable for outage submission and retrieval. Automated dispatch instructions sent via Dispatch Service will be unavailable. The IESO will manually dispatch by phone as necessary. The Dispatch Service Web UI users may get disconnected and will need to login and verify connected after the outage.Report site will be unavailable and publication of public and confidential Reports will be delayed.The Eligible Energy Limited Resource Optimization (EELR) run of the Day-Ahead Commitment Process (DACP) DAOS will not occur:
  • EELRs will be unable to resubmit their offers for consideration in the DACP after the initial DAOS run
  • If the initial DAOS run is successful, it will be considered the Schedule of Record
New person registration in the Registration Application will not be available.
October 28, 2019
11:20 - 12:23 IESO Portal Loss of access to the IESO Portal will impact the following applications:
  • Transmission Rights Auction (TRA) application will be unavailable
  • All on-line collaboration communities will be unavailable
  • Prudential Manager used to monitor and retrieve prudential information will be unavailable


EMI application used to submit bids, offers, schedules and forecasts will be unavailable. Market participants should confirm their bids and offers once the outage is completed.
EMI application used to submit bids, offers, schedules and forecast will be unavailable.EMI API application used to submit bids, offers, schedules and forecast will be unavailable.OCSS Web User Interface will be unavailable for outage submission and retrieval. Automated dispatch instructions sent via Dispatch Service will be unavailable. The IESO will manually dispatch by phone as necessary. The Dispatch Service Web UI users may get disconnected and will need to login and verify connected after the outage.Report site will be unavailable and publication of public and confidential Reports will be delayed.The Eligible Energy Limited Resource Optimization (EELR) run of the Day-Ahead Commitment Process (DACP) DAOS will not occur:
  • EELRs will be unable to resubmit their offers for consideration in the DACP after the initial DAOS run
  • If the initial DAOS run is successful, it will be considered the Schedule of Record
New person registration in the Registration Application will not be available.