Which of the following best defines throughput in operations?

Throughput in operations refers specifically to the speed at which products flow through a system. This concept is crucial in understanding how effectively a manufacturing or service process operates, as it captures the rate of production or completion of tasks within a given timeframe. High throughput indicates that more products are being processed within that time, which generally signifies an efficient operation.

When considering the other options, while the total number of products produced in a year can give a measure of output, it does not convey the importance of speed and efficiency in production. Similarly, the overall efficiency of a workforce focuses on how well individuals perform their tasks rather than the flow of products through the operational system. Lastly, the percentage of defective products produced pertains to quality control rather than throughput, which strictly addresses the rate of production. Thus, option B accurately encapsulates the essence of throughput by highlighting the flow and pace of products in operations.