1. 1 10/1/2016 Cut-Over Milestones 01 September 2010Market Readiness Seminar

2. 2 01 September 2010 Cutover Tasks Complete (08/13) Registration Deadline for CRRAH to participate in December CRR Monthly Auction (Protocol 16.8.2) (08/16) ERCOT releases Outage Scheduler to Market  TSPs/QSEs can enter outages in Outage Scheduler via Web Service or UI  TSPs/QSEs are responsible for verifying outages imported to Nodal Systems and correcting any missed/incorrect outages by 09/17/2010 (09/01) Network Model Go-Live (Protocol 3.10 ) (09/02) Begin interim update process for Network Model Changes  From 09/02 forward until Go-Live any Model changes submitted to ERCOT prior to Go-Live will leverage the interim update process. (09/01) CRR Activity Calendar to MIS  MPs can retrieve the CRR Activity Calendar from MIS public with a valid Digital Certificate Cutover Update

3. 3 Market Readiness Seminar01 September 2010 Next 2 Weeks (09/08) Deadline for PCRR NOIE Contract Eligibility (09/17) Outages are synched between Zonal and Nodal.  Market Participants maintain synch of outages between Zonal and Nodal systems thru 12/02 (dual entry) Next Month Summary (CREDIT) ERCOT assesses each CPs credit worthiness for the Dec CRR Auction ERCOT posts ACLs daily for CRR December monthly auction to CRR  CRRAH able to retrieve ACLs from CRR system each business day.  MPs can post additional collateral until 11/08/2010 for Dec 2010 CRR Auction (CRR) ERCOT begins accepting PCRR Nominations for December Monthly Auction ERCOT shall allocate PCRRs to NOIEs for the 2010 December Monthly Auction and publish to MIS ERCOT shall post CRR Network Model for the 2010 December Monthly Auction to MIS ERCOT to post December 2010 Monthly Auction Notice to MIS Cutover Update – Upcoming Activities

4. 4 Market Readiness Seminar01 September 2010 Next Month Summary Cont’d (OUTAGES) December Outages pulled for CRR Network Model (for PCRR Allocation) (NETWORK MODEL) Network Model built for CRR Allocation and Auction Network Operations Model posted to TSP Citrix location and TSPs begin validation process (ERCOT) ERCOT begins test data clean up from Market Trials  CRR Test Data ERCOT performs MIS backend reconfigurations (10/03/2010 – 10/11/2010)  Market Participants will not have access to the MIS UI and EWS Get Reports functionality.  Market Participants will need to use the direct links (listed on next slide) or Citrix to access system applications.  All other EWS will be left on and from 10/1 up until the First Run Date as defined in EMIL of the CDR report, the EWS will return ‘no reports found’ during that time. MIS UI and EWS Get Report Go-Live (10/12/2010)  Postings will be made available based on the EMIL posting date going forward  Postings live prior to 10/12/2010 will continue to be made available at this time.  Market Participants will only have access to go-live posting data. Data from Market Trials activities is no longer available for download. Cutover Update – Upcoming Activities

5. 5 URLs to be used during cutover activities in October: – Network Model via Citrix: – https://gateway.ercot.com/vpn/index.html https://gateway.ercot.com/vpn/index.html – Market Manager User Interface: – https://mis.ercot.com/mmsui/mmsui/displayTradesLanding.action https://mis.ercot.com/mmsui/mmsui/displayTradesLanding.action – Outage Scheduler Application: – https://mis.ercot.com/osrui/osrui/Summary.action https://mis.ercot.com/osrui/osrui/Summary.action – CRR Application (MUI): –https://mis.ercot.com/crr/mui/ListAllUserMessage.do - direct link for CRRAHshttps://mis.ercot.com/crr/mui/ListAllUserMessage.do –https://mis.ercot.com/crr/mui/editSMPCreditLimit.do - direct link for CPshttps://mis.ercot.com/crr/mui/editSMPCreditLimit.do –Web Services Endpoint URL: –https://misapi.ercot.com/2007-08/Nodal/eEDS/EWShttps://misapi.ercot.com/2007-08/Nodal/eEDS/EWS Cut-Over – MIS UI and EWS Get Report Reconfiguration Details 01 September 2010Market Readiness Seminar