3 1. DEFINING PROGRAM OBJECTIVES The starting point in the Utility Infrastructure Resiliency Playbook (Playbook) for building potential resiliency programs is to develop a clearly defined singular or set of objectives. This current section introduces this concept and assists the reader in undertaking this effort. Program Vocabulary We begin with the introduction of basic reliabilityrelated vocabulary and depict the interconnection in Exhibit 1.1. Reliability: long-term and operational steps that reduce the probability of power interruptions and prevent loss of customer load (#186, pg. 3) Reliability is measured using three characteristics: 1. Frequency: how many outages happen 2. Duration: the length of time before the interrupted service is restored 3. Scale or Impact: the number of customers affected by an outage Along with reliability, resiliency is defined as: Resiliency: steps taken to reduce outage damage and hasten restoration or recovery to shorten outage duration (#186, pg. 3) More generally, resiliency is the recovery characteristics of infrastructure and operations, which avoid or minimize interruptions of service during an extraordinary event. If an investment avoids or minimizes service interruptions in the absence of an extraordinary event, it is a routine reliability investment. Resilient infrastructure does more than one thing well. A resilience investment pays for itself and creates value for ratepayers, even when it is not being used (#216). In other words, power system resilience should impact the number of outages (frequency), the number of customers affected by an outage (scale), and the length of time before interrupted service is restored (duration). Resiliency techniques include hardening; increased labor force; standby equipment; restoration materials; enhanced communication, planning, and coordination; advanced technologies, etc. A key resiliency technique is hardening which is defined as physical changes that improve the durability and stability of specific pieces of electric distribution or transmission system infrastructure. In general, it refers to constructing or improving an overhead system asset or facility beyond the typical National Electrical Safety Code (NESC) requirements for a particular geography. Examples include undergrounding, vegetation management, pole replacement, etc. Exhibit 1.1 Reliability Related Vocabulary
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