Final answer:
The limit on the number of posting errors is part of the Performance Metrics component, which quantifies acceptable job performance standards.
Step-by-step explanation:
The statement "No more than three posting errors per month can occur on average" would most aptly belong to the Performance Metrics component of a job description. This component is used to set standards for acceptable job performance, often in measurable terms. In this context, the limit on the number of posting errors is a way to quantify the worker's accuracy and efficiency when handling postings and is used to assess their performance.