Explain the concept of 'equivalent availability' as a key performance indicator (KPI) for industrial plants.

Equivalent availability (EA) is a key performance indicator (KPI) used to measure the actual operational availability of an industrial plant or equipment, taking into account both planned and unplanned downtime, as well as derated operating conditions. It represents the percentage of time that the plant or equipment is capable of operating at its full rated capacity. Unlike simple availability, which only considers whether a system is running or not, equivalent availability accounts for partial load operation. The formula for calculating equivalent availability is: EA = (Energy Produced / Energy that could have been produced at full capacity) 100%. Energy Produced is the actual energy generated (e.g., electricity in a power plant, product output in a chemical plant) during the period of interest. Energy that could have been produced at full capacity is the theoretical energy that the plant or equipment would have produced if it had operated continuously at its full rated capacity during the same period. If a power plant experiences a forced outage due to equipment failure, the EA decreases. Similarly, if the plant is derated (operating at reduced capacity) due to maintenance or other factors, the EA also decreases. The EA provides a more comprehensive measure of the plant's overall performance than simple availability because it reflects the impact of both downtime and derated operation. A high equivalent availability indicates that the plant is operating efficiently and reliably, minimizing downtime and maximizing production. Regular monitoring of EA helps identify areas for improvement in maintenance practices, operational procedures, and equipment reliability. For instance, if a power plant has a low EA due to frequent forced outages of a specific turbine, the plant may invest in upgrades to improve the turbine's reliability and increase the plant's overall EA. It differs from other measures such as Mean Time Between Failures (MTBF) and Mean Time To Repair (MTTR), by looking at the capacity weighted operational time as a percentage of the total time.