methodology) without defining the means (e.g. using the West-wide System Model (WSM)) by which the objective must be met. In keeping with FERC’s direction, the DT concluded that although the use of a single Interconnection-wide model, such as the WSM or its successor, may represent an ideal practice, to do so failed to consider: 1) the existing variations in SCADA data from one RC Area to another, 2) the added propensity for error when modeling unnecessary elements, 3) the added inefficiencies of requiring an RC to model elements having no impact on its RC Area, and 4) the potential costs of compliance. Rather, relying on FERC Order 672, P. 328 and P. 330, the DT opted for an approach taking in to consideration “implementation cost [and] historical regional infrastructure design” while achieving the reliability objective “effectively and efficiently.” Further, the DT chose the methodology approach over specifying a model as the later approach could violate the measurability mandate of FERC Order 672, P. 327. Since such a requirement would require use of the entire specified model, defining the four-corners of such a model and measurement thereof would add ambiguity resulting in a requirement without clear measure. Finally, the DT chose the methodology approach because of its viability in an uncertain climate. If use of a specific model was mandated, the standard could be rendered ineffective if the specific model was abandoned. Even if use of “its successor” were mandated, compliance would be held at bay until the validity of “its successor” was determined.
methodology) without defining the means (e.g. using the West-wide System Model (WSM)) by which the objective must be met. In keeping with FERC’s direction, the DT concluded that although the use of a single Interconnection-wide model, such as the WSM or its successor, may represent an ideal practice, to do so failed to consider: 1) the existing variations in SCADA data from one RC Area to another, 2) the added propensity for error when modeling unnecessary elements, 3) the added inefficiencies of requiring an RC to model elements having no impact on its RC Area, and 4) the potential costs of compliance. Rather, relying on FERC Order 672, P. 328 and P. 330, the DT opted for an approach taking in to consideration “implementation cost [and] historical regional infrastructure design” while achieving the reliability objective “effectively and efficiently.” Further, the DT chose the methodology approach over specifying a model as the later approach could violate the measurability mandate of FERC Order 672, P. 327. Since such a requirement would require use of the entire specified model, defining the four-corners of such a model and measurement thereof would add ambiguity resulting in a requirement without clear measure. Finally, the DT chose the methodology approach because of its viability in an uncertain climate. If use of a specific model was mandated, the standard could be rendered ineffective if the specific model was abandoned. Even if use of “its successor” were mandated, compliance would be held at bay until the validity of “its successor” was determined.