Retail SLA Proposed Changes RMS/TDTWG September 2008 Trey Felton IT Account Manager

2 Apr – Jun 2008

3 Sample Data For complete data set see: Retail SLA_Transaction Stats.xls

4 Weekend Transaction Volume during Outage Window Timeframes (1-year average vs 3-month average) Current Release Window Proposed Release Window

5 Summary SLA Proposed Changes –Add 6 hours to Week 1 Currently 12 hours –Move 36-hr release window to Week 4 Currently in Week 2—busiest week –Add a 12-hour outage window in Week 5s (Mar/May/Aug/Nov) Not in current SLA November will not be used for a release or week 5 outage Rationale –5-week Months become general outline for major releases (Mar/May/Aug/Dec) Extra weekend gives additional outage window opportunity –Remaining months will be reserved for minor releases

6 Additional Considerations For 2009 –Move November Week 4 Outage to December Week 2 To accommodate for Thanksgiving Holiday –Move May Release up 1 week (to Week 3) To accommodate for Memorial Day –Analyze Quarterly Release concept For 2010 –Reduce monthly minor release windows if possible

7 Proposed Release Calendar (2009)

8 TDTWG Recommendations Limit Maintenance Window request to 15 hrs –Yes Reduce Release Outage to 30 hrs –Cannot Support Marketrak available 8am – Noon on Saturday –Yes Have 1 weekend a month with zero outages –With our current systems, ERCOT cannot support –Targeted for 2010

9 Proposed Maintenance/Release Windows for 2009 MAINTENANCE  1 st and 2 nd Sunday– 6:00am until 9:00pm Sunday (15 hours)  Option 2: Sunday– 9:00am until 12:00am Monday (15 hours)  3 rd and 5 th Sunday—8:00am until 8:00pm (12 hrs)  Option 2: Sunday—10:00am until 10:00pm (12 hrs)  RELEASE: 4 th weekend– 12:00pm Saturday until 12:00am Monday (36 hours)  Option 2: 10:00am Saturday until 10:00pm Sunday (36 hours)

10 Maintenance Outages (since Jan 1, 2008) ERCOT Proposed SLA (18 hours) Current SLA (12 hours) Average = 9.8 hrs TDTWG Proposed (15 hours)

11 Current / Proposed SLA (36 hours) TDTWG Proposed (30 hours) Releases ( ) Average = 26.4 hrs 20% took more than 36 hrs 33% took more than 30 hrs

12 Marketrak

13 Impacts to Data Extracts SLA Maintenance Windows: –1st, 3rd, and 4th Sunday of each month – 8:00am until 8:00pm (12 hours) New Maintenance Windows –1st and 2nd Sunday—6:00am until 9:00pm (15 hours) –3rd and 5th Sunday—8:00am until 8:00pm (12 hours) Release Window: –2nd weekend of each month – 12:00pm Saturday until 12:00am Monday (36 hours) New Release Window: –4th weekend*– 12:00pm Saturday until 12:00am Monday (36 hours) Availability Breakdown: Gross minutes per year = 525,600 (unchanged) Reserved maintenance outage minutes per year = 25,920 (new SLA 32,940) Reserved release outage minutes per year = 25,920 (new SLA 23,760) 525,600 – 51,840 = 473,760 net availability minutes per year (New SLA) 525,600 – 56,700 = 468,900 net availability minutes per year 99% availability = 4,737 unplanned outage minutes per year, or 78.9 hours (if all available maintenance and release windows are used) 99% availability = 4,689 unplanned outage minutes per year, or hours (if all available maintenance and release windows are used) (New SLA)

14 Backup Slides

15 Release Outage (apportioned time) Start TimeSat 12:00pm Shut down apps and clear queues1.5 hrs New Code Migration4 - 6 hrs Bring Systems Back Up / Tech Verification1 hr Production Verification4 hrs Rollback Contingency1 - 4 hrs Minimum Time Needed 11.5 – 16.5 hrs Variations June Release: Planned 11 hrs, Actual 24.8 hrs (Prod verification failure; rollback) July Release: Planned 9 hrs, Actual 9 hrs Average Release has been 24 hrs (since Jan 1, 2008)

Net Service Availability 15 July, 2008ERCOT Confidential

17 Releases (2008) Current / Proposed SLA (36 hours) Average = 24 hrs TDTWG Proposed (30 hours)