Information Technology Report Dave Pagliai Manager, IT Support Services October 2015 ERCOT Public

2 October 2015 Incident Report Highlights Service Availability – September Market Data Transparency IT systems met all SLA targets, with the exception of XRetail API (Find ESIID – 97.8%) Incidents & Maintenance – September/October  09/20/15 – UNIX Production frame failure in Taylor data center  09/21/15 – Unplanned Maintenance (Site Failover)  10/02/15 – Planned Maintenance (Site Failover)  10/08/15 – Planned Maintenance (Site Failover – External Web Services)  10/09/15 – Planned Maintenance (Site Failover – MIS)  10/11/15 – Planned Maintenance (Site Failover – ercot.com, MPIM, Retail API)

3 ERCOT PublicOctober 2015 Incident Report Highlights Report NameFrequencyEMIL ID Report Type ID Missed Intervals Number of Intervals Missed Consolidated Transmission Outage ReportChron - Hourly NP3-157-CD /09/ : /09/ :004 Forecasted Temperature Adjusted Dynamic RatingsChron - Hourly NP3-217-CD /09/ : /09/ :004 Hourly Balancing Authority Operations ReportChron - Hourly EIA-930-CD /09/ : /09/ :004 Hourly Resource Outage CapacityChron - Hourly NP3-233-CD /09/ : /09/ :004 Hourly State Estimator Phase Shifter InformationChron - Hourly NP6-622-CD /09/ : /09/ :004 Load Forecast Distribution FactorsChron - Hourly NP4-159-CD /09/ : /09/ :004 NSA Active ConstraintsChron - 5 Minutes when neededNP6-6-CD /20/ : /21/ :30116 NSA Inactive ConstraintsChron - 5 Minutes when neededNP5-911-CD /20/ : /21/ :30116 QSE Ancillary Services Capacity MonitorChron - 5 MinutesNP8-143-CD /09/ : /09/ :1554 Real Time Dynamic Rating DataChron - 15 MinutesNP6-215-CD /09/ : /09/ :4516 RUC Buy-Back Hours Chron - Hourly NP5-513-CD /09/ : /09/ :006 Seven-Day Load Forecast by Forecast ZoneChron - Hourly NP3-560-CD /09/ : /09/ :004 Seven-Day Load Forecast by Weather Zone Chron - Hourly NP3-561-CD /09/ : /09/ :004 Short-Term System Adequacy Report Chron - Hourly NP3-763-CD /09/ : /09/ :004 State Estimator Bus Voltages Chron - Hourly NP6-627-CD /09/ : /09/ :004 State Estimator Load Report - DC Ties Flows Chron - Hourly NP6-626-CD /09/ : /09/ :004 State Estimator Load Report - Total ERCOT Generation Chron - Hourly NP6-625-CD /09/ : /09/ :004 State Estimator Real-Time Transmission Line FlowsChron - 5 MinutesNP6-619-CD /09/ : /09/ :4548 State Estimator Switch StatusChron - Hourly NP6-93-CD /09/ : /09/ :004 System-Wide Demand Chron - Hourly NP6-235-CD /09/ : /09/ :004 Temporarily Removed Contingencies Chron - Hourly NP5-649-CD /09/ : /09/ :004 Topology ConsistencyChron - 5 MinutesNP6-291-CD /09/ : /09/ :4548 Unconfirmed Ancillary Service Trades Chron - Hourly NP4-439-CD /09/ : /09/ :0013 Unconfirmed Capacity Trades Chron - Hourly NP4-437-CD /09/ : /09/ :00 21/09/ : /09/ :00 10 Unconfirmed Energy Trades Chron - Hourly NP4-438-CD /09/ : /09/ :009 Wind Generation Resource Power Potential Forecast Chron - Hourly NP4-731-SG /09/ : /09/ :0010 Wind Power Production - Actual 5-minute averaged valuesChron - 5 MinutesNP4-733-CD /09/ : /09/ :4549 Wind Power Production - Hourly averaged actual and forecasted values Chron - Hourly NP4-732-CD /09/ : /09/ :004