ERCOT Lodestar Extracts Timing Recommendation ERCOT May 24, 2005

Overview Lodestar Extracts Current Extract Process for Lodestar Extracts from Data Archive ERCOT Recommended Process for Lodestar Extracts from ODS ERCOT Recommended Timing Process for Lodestar Extracts from ODS

Lodestar Extracts SCR 727 ESIID Extract Resource ID Extract (New) Load Extract Generation Extract Settlements & Billing Extract Settlement Input Data Extract (New) Shadow Pricing Extract Public Reference Table Extract (New)

SCR 727 ESIID Extracts Current Process from Data Archive Data Type: ESIID level data Data Flow Process: At 5:00AM, Lodestar Data Archive process runs to capture the existing records with addtimes/timestamps of previous day 4:00AM through current day 3:59:59AM Frequency: Generation and posting of extract occurs daily and is posted to market participants after being audited Extract Creation Trigger: Automatically by data inserts/updates/deletes

Load, Generation, and Settlements & Billing Extracts Current Process from Data Archive Data Type: – MOS and bill determinant trade date (Settlement Input Data) data as early as two days after operating day and may receive data changes up until the initial settlement – Data Aggregation and Settlement interval data outputs Data Flow Process: At 5:00AM, Lodestar Data Archive process runs to capture the existing records with addtimes/timestamps of previous day 4:00AM through current day 3:59:59AM Frequency: Extract process occurs Tuesday – Saturday only and is modified as necessary for holidays Extract Creation Trigger: By market participants scheduling the extract; Not dependent on Data Archive Process

Load, Generation, and Settlements & Billing Extracts Current Process from Data Archive – con’t Known Reasons for Improvement: – Potential for trade date outputs to be contained in multiple extracts – No dependency on settlement trade date approvals allowing trade date outputs to be received in multiple extracts with different addtimes/timestamps to account for backouts/reruns of unapproved settlements prior to posting an approved statement – Inconsistent synchronization of SCR 727 ESIID Extract data in conjunction with corresponding Load & Generation Extract postings

Shadow Pricing Extracts Current Process from Data Archive Data Type: Contains shadow pricing data Data Flow Process: At 5:00AM, Lodestar Data Archive process runs to capture the existing records with addtimes/timestamps of previous day 4:00AM through current day 3:59:59AM Frequency: Extract process occurs Tuesday – Saturday only and is modified as necessary for holidays Extract Creation Trigger: Automatically by data inserts

SCR 727 ESIID Extracts and Resource ID Extracts ERCOT Recommended Process from ODS Data Type: – SCR 727 ESIID Extract contains ESIID level data (granular data) – Resource ID Extract contains Resource ID level data (granular data) - New Data Flow Process: Continuous data flow from the Lodestar Source System -> Replicated Source System -> Lodestar ODS capturing intraday data updates and point in time selectivity Frequency: Generation and posting of extract occurs daily and is posted to market participants after being audited Extract Creation Trigger: Automatically by data inserts/updates/deletes

Recommended Changes: – Data load time window for the granular data Point in Time is captured by the initiation of granular data changes (Lodestar Batch usage data loading) at SYSDATE -3 to the next day’s initiation of granular data changes (Lodestar Batch usage data loading) – Produce on a 2 day lag from the data load time window stop time to accommodate for extract trade date synchronization and Lodestar ODS data synchronization including scheduled & unscheduled environment maintenance and troubleshooting data & system issues – Data included within daily extract is synchronized to one posting of a complete batch of trade dates for the Load, Generation and Settlements & Billing Extracts Timing proposal discussed with DEWG at February - May 2005 meetings SCR 727 ESIID Extracts and Resource ID Extracts ERCOT Recommended Process from ODS – con’t

SCR 727 ESIID Extract and Resource ID Extract Timing Change Day Extract is Generated and Published Current Data Addtime Time Window Recommendation Data Addtime Time Window MondaySunday 4:00AM - Monday 3:59:59AMFriday ~4:00:00 AM – Saturday ~3:59:59 AM TuesdayMonday 4:00AM - Tuesday 3:59:59AMSaturday ~4:00:00 AM – Sunday ~3:59:59 AM WednesdayTuesday 4:00AM - Wednesday 3:59:59AMSunday ~4:00:00 AM – Monday ~3:59:59 AM ThursdayWednesday 4:00AM - Thursday 3:59:59AMMonday ~4:00:00 AM – Tuesday ~3:59:59 AM FridayThursday 4:00AM - Friday 3:59:59AMTuesday ~4:00:00 AM – Wednesday ~3:59:59 AM SaturdayFriday 4:00AM - Saturday 3:59:59AMWednesday ~4:00:00 AM – Thursday ~3:59:59 AM SundaySaturday 4:00AM - Sunday 3:59:59AMThursday ~4:00:00 AM – Friday ~3:59:59 AM

Load, Generation, and Settlements & Billing Extracts ERCOT Recommended Process from ODS Data Type: – Load and Generation Extracts contain all outputs for a trade date in one extract – Settlement & Billing Daily Extract contains Settlements input data used and output data created for each approved trade date for all trade dates within a batch run becoming a complete trade date specific extract – Provide complete batch run with all Trade Dates approved accounting for subsequent Trade Date reruns prior to Settlements Approval Data Process Flow: Continuous data flow from the Lodestar Source System -> Replicated Source System -> Lodestar ODS capturing intraday data updates and point in time selectivity

Load, Generation, and Settlements & Billing Extracts ERCOT Recommended Process from ODS – con’t Frequency: Generation and posting of extract occurs daily and is posted to market participants after being audited Extract Creation Trigger: By market participants scheduling the extract Recommended Changes: – With extract creation and posting delay, No additional logic necessary to accommodate for receipt of unapproved Trade Date data and extract schedule changes – Up to an additional 3 day lag to the delivery timeline to accommodate for synchronization of extracts with approved settlement data (weekends & holidays), Lodestar ODS data synchronization including scheduled & unscheduled environment maintenance and troubleshooting data & system issues

Recommended Changes: – Consistent synchronization of SCR 727 ESIID Extract data and RID Extract data in conjunction with corresponding Load & Generation Extract postings – Granular data necessary to shadow settle is posted 2 days prior to the Aggregation and Settlement extracts Timing proposal discussed with DEWG at May 2005 meeting Load, Generation, and Settlements & Billing Extracts ERCOT Recommended Process from ODS – con’t

Load, Generation, and Settlements & Billing Extracts Timing Change Day Extract is Produced and Published Current Data Addtime Time Window Batch Trade Dates for due Settlement Statements Recommendation Data Time Window MondayNo extract produced and publishedThursday, Friday, SaturdayWednesday Batch Trade Dates TuesdayFriday 12:30 AM - Monday 12:29:59AM (Fri, Sat, Sun batch) SundayThursday Batch Trade Dates WednesdayMonday 12:30AM - Tuesday 12:29:59AM (Mon batch) MondayFriday Batch Trade Dates ThursdayTuesday 12:30AM - Wednesday 12:29:59AM (Tues batch) TuesdaySaturday Batch Trade Dates FridayWednesday 12:30AM - Thursday 12:29:59AM (Wed batch) WednesdaySunday Batch Trade Dates SaturdayThursday 12:30AM - Friday 12:29:59AM (Thurs batch) No approved statements posted Monday Batch Trade Dates SundayNo extract produced and publishedNo approved statements posted Tuesday Batch Trade Dates

Settlement Input Data Extracts (New) ERCOT Recommended Process from ODS Data Type: Contains all input data passed from MOS to the settlement system or entered by settlement personnel; data that is currently provided in the Settlement & Billing Extracts Data Flow Process: Continuous data flow from the Lodestar Source System -> Replicated Source System -> Lodestar ODS capturing intraday data updates and point in time selectivity Frequency: Generation and posting of extract occurs daily and is posted to market participants after being audited Extract Creation Trigger: By market participants scheduling the extract

Settlement Input Data Extracts (New) ERCOT Recommended Process from ODS – con’t Recommended Changes: – Redefines Settlement & Billing Extract to only provide complete approved trade date inputs and outputs synchronized with the Load and Generation Extracts – Data load time window is captured by the initiation of granular data changes (Lodestar Batch usage data loading) at SYSDATE -3 to the next day’s initiation of granular data changes (Lodestar Batch usage data loading)

Settlement Input Data Extracts Timing Change Day Extract is Produced and Published Current Settlements & Billing Extract Data Addtime Time Window Recommendation New Extract Data Addtime Time Window MondayNo extract produced and publishedFriday ~4:00:00 AM – Saturday ~3:59:59 AM TuesdayFriday 12:30 AM - Monday 12:29:59AM (Fri, Sat, Sun batch) Saturday ~4:00:00 AM – Sunday ~3:59:59 AM WednesdayMonday 12:30AM - Tuesday 12:29:59AM (Mon batch) Sunday ~4:00:00 AM – Monday ~3:59:59 AM ThursdayTuesday 12:30AM - Wednesday 12:29:59AM (Tues batch) Monday ~4:00:00 AM – Tuesday ~3:59:59 AM FridayWednesday 12:30AM - Thursday 12:29:59AM (Wed batch) Tuesday ~4:00:00 AM – Wednesday ~3:59:59 AM SaturdayThursday 12:30AM - Friday 12:29:59AM (Thurs batch) Wednesday ~4:00:00 AM – Thursday ~3:59:59 AM SundayNo extract produced and publishedThursday ~4:00:00 AM – Friday ~3:59:59 AM

Shadow Pricing Extracts ERCOT Recommended Process from ODS Data Type: Contains shadow pricing data Data Flow Process: Continuous data flow from the Lodestar Source System -> Replicated Source System -> Lodestar ODS capturing intraday data updates and point in time selectivity Frequency: Generation and posting of extract occurs daily and is posted to market participants after being audited Extract Creation Trigger: Automatically by data inserts Recommended Changes: – Data load time window is captured by the initiation of granular data changes (Lodestar Batch usage data loading) at SYSDATE -3 to the next day’s initiation of granular data changes (Lodestar Batch usage data loading)

Settlement Input Data Extracts Timing Day Extract is Produced and Published Current Data Addtime Time Window Recommendation Data Addtime Time Window MondayNo extract produced and publishedFriday ~4:00:00 AM – Saturday ~3:59:59 AM TuesdayFriday 12:30 AM - Monday 12:29:59AM (Fri, Sat, Sun batch) Saturday ~4:00:00 AM – Sunday ~3:59:59 AM WednesdayMonday 12:30AM - Tuesday 12:29:59AM (Mon batch) Sunday ~4:00:00 AM – Monday ~3:59:59 AM ThursdayTuesday 12:30AM - Wednesday 12:29:59AM (Tues batch) Monday ~4:00:00 AM – Tuesday ~3:59:59 AM FridayWednesday 12:30AM - Thursday 12:29:59AM (Wed batch) Tuesday ~4:00:00 AM – Wednesday ~3:59:59 AM SaturdayThursday 12:30AM - Friday 12:29:59AM (Thurs batch) Wednesday ~4:00:00 AM – Thursday ~3:59:59 AM SundayNo extract produced and publishedThursday ~4:00:00 AM – Friday ~3:59:59 AM

Public Reference Table Extracts (New) ERCOT Recommended Process from ODS Data Type: Contains full tables of non-interval market level data (ex. TDSP, STATION, CMZONE, etc.) from Lodestar extracts Data Flow Process: Continuous data flow from the Lodestar Source System -> Replicated Source System -> Lodestar ODS capturing intraday data updates and point in time selectivity Frequency: Generation and posting of extract occurs daily and is posted to market participants after being audited; only one daily extract available (no historical postings); delivery timeline same as SCR 727 ESIID and Resource ID Extracts Extract Creation Trigger: Automatically by data inserts/updates/deletes

What’s Next? Comments, Feedback, Questions ERCOT complete Analytical Designs of Execution Phase for the following projects: – PR – Resource ID Extract – PR – SCR 727 Phase II (SCR 727 ESIID Extract and Public Reference Table Extract) – PR 40042_06 – Lodestar Batch Extracts (Load, Generation, Settlements & Billing, Settlement Input Data, and Shadow Pricing Extracts)