Which KPI helps assess the availability of parts for maintenance?

• A. Cost variance
• B. Lead time
• C. Quality defect rate
• D. Fill rate

Answer: (D)

The main idea here is measuring whether maintenance parts are actually on hand when needed. Fill rate does exactly that by showing the percentage of maintenance part requests that can be filled from existing inventory without backorders. A high fill rate means parts are readily available to keep work orders moving, while a low fill rate indicates frequent stockouts and delays.

Lead time, by contrast, tells you how long it takes to get parts after you place an order, which matters for planning but doesn’t directly reflect whether parts are available in stock at the moment of need. Quality defect rate focuses on the quality of parts, not their availability. Cost variance looks at budget performance rather than stock readiness.