IEC 61850 has been promoted as an interoperability standard, but to date, interoperability among vendors has been achieved only at a communications level. When actually implementing the various substation functions, the user could be forced to change methods between vendors due to the flexibility and options provided for in IEC 61850. Additionally, IEC 61850 requires significant changes to the design, construction, and commissioning of a substation. Hard-wired signals are replaced by logical bits being communicated over Ethernet networks, documentation and naming conventions are distinctly different from existing substation practice, and device functionality could be assigned, and even migrate, in an operational environment. Users will also require a methodology to integrate IEC 61850 and non-IEC 61850 operational practices in their system as both approaches will have to exist side by side for many years. This recommended practice will provide a starting point for those users who would like to migrate to an IEC 61850 substation approach and establish baseline functionality to which vendors could adhere with confidence of achieving interoperability with other vendors.