Transmission System Planning The links on this page provide access to information about Transmission Services planning studies as required by CFR 18 part 37.6(e) and the system planning process as required by the Open Access Transmission Tariff, Attachment K. Transmission Planning Studies View lists of transmission studies, specific network studies, and transmission study performance metrics. Attachment K Planning Process View information about the Open Access Transmission Tariff Attachment K Planning Process that is currently underway. Related Information Links to related information on the site. Interconnection Information Open Access Transmission Tariff Transmission Services Business Practices Regional Transmission Projects Map