Lateness is defined as the difference between the actual completion time and the due date for a job. If the completion time is greater than the due date, the lateness is positive, indicating a delay. If the completion time is earlier than the due date, the lateness is negative, indicating an early completion. It is a key performance metric used in scheduling and job management.
In contrast, flow time refers to the total time a job takes from arrival to completion, and processing time refers to the time required to actually process a job. Lead time represents the total time required from order placement to delivery, which is broader than lateness.