1. Lead from the front Texas Nodal http://nodal.ercot.com 1 Texas Nodal Market Implementation Program CRR Detailed Design Document Review Process Compiled by CRR Project Team – Shawna R. Jirasek February 23, 2007

2. Lead from the front Texas Nodal http://nodal.ercot.com 2 Transition Plan – Detail System Design and Other Detail System Design Documentation per Transition Plan –“Document that provides the full details of the components in the system and how they interact with each other to implement the conceptual design. The TPTF will review these documents and comment on any possible compliance issues with applicable protocols. ERCOT shall review the comments and make appropriate corrections to the document.” CRR Project Detail System Design Documentation for Review –Market Operator Interface (MOI) –Market User Interface (MUI) –Database –Data Interface –Calculation CRR Project Documentation that Provides Additional Detail –Database –Calculation Contains Nexant Intellectual Property (IP)

3. Lead from the front Texas Nodal http://nodal.ercot.com 3 ERCOT Document Classification PUBLIC –Information officially released for widespread public disclosure, either by requirement or as the result of an ERCOT management decision. ERCOT LIMITED –Information intended for internal use within ERCOT. –Release of this Information represents a minimal risk to ERCOT or others entrusting Information to ERCOT. –If not designated, the default classification for any Information is ERCOT Limited. ERCOT CONFIDENTIAL –Information generated in the course of business, for which inadvertent access or disclosure represents a medium to significant risk to ERCOT or others entrusting Information to ERCOT. –Specifically includes all Information that is “Protected Information” under the ERCOT Protocols. ERCOT RESTRICTED –Information, whose disclosure would have severe legal, regulatory, operational, security, financial, or other such repercussions for ERCOT or others entrusting Information to ERCOT.

4. Lead from the front Texas Nodal http://nodal.ercot.com 4 CRR Document Organization ERCOT LimitedERCOT Confidential # PagesSize (MB)# PagesSize (MB) MOI28492KB MUI29314KB Calculation231.29561.37 Data Interface721.92 Database251.8251013.5 Requires ERCOT and Nexant NDA Requires ERCOT NDA Contains Nexant IP

5. Lead from the front Texas Nodal http://nodal.ercot.com 5 How to get Documentation ERCOT Limited (Detail System Design Documents) –Send a request to Carrie Tucker –Once the NDA is executed, the CRR Project Team will send the ERCOT Limited document(s) to you ERCOT Confidential (Additional Details to Design Documents) –Send a request to Carrie Tucker (ctucker@ercot.com)ctucker@ercot.com –ERCOT Legal will send you an NDA to sign and return –Once the NDAs are executed, the CRR Project Team will send the ERCOT Confidential document(s) to you What to do if you have comments upon review of the document(s) –“The TPTF will review these documents and comment on any possible compliance issues with applicable protocols. ERCOT shall review the comments and make appropriate corrections to the document.” – Transition Plan –Send your comments to Beth Garza and Shawna R. Jirasek bgarza@ercot.com and sjirasek@ercot.combgarza@ercot.comsjirasek@ercot.com