Unlike traditional, “accounting” based measurements, this metric asks the question: “Does the operation run when it has to?” In other words, is the operation available to produce what the customer wants? We’re not interested in machine utilization, as that can lead to over production, which is the biggest (and most common) waste in operations.
OA simply measures the number of good units of output versus what the customer demand is, and expresses it in terms of a percentage. When the OA % is below target, we have to ask ourselves some questions: ”What happened? What is the impact on the customer? How are we going to recover?”
Note that in knowledge or service based work, this metric is equally useful…every process has a customer, so just figure out what that customer demand is and measure your ability to meet it! It can be number of student registrations, number of patients seen at a clinic or number of vehicles moving down the assembly line…doesn’t matter!