Which of the following is an example of a key performance indicator (KPI)?

The employee turnover rate is a critical indicator of an organization's health and effectiveness regarding its workforce management. It measures the percentage of employees who leave an organization within a specific period, reflecting various factors such as job satisfaction, engagement, and the overall work environment. High turnover rates can signal underlying issues, such as poor leadership, lack of career development opportunities, or an undesirable workplace culture, which can directly affect productivity and financial performance.

By monitoring this KPI, organizations can identify trends, correlate turnover with other factors, and implement strategic HR initiatives to improve employee retention. Furthermore, addressing turnover is crucial as recruiting and training new employees incurs significant costs, emphasizing the importance of using the turnover rate as a metric for assessing HR efficiency and effectiveness.

The other options do not serve as effective KPIs for the same reason. The total number of employees provides a snapshot of the workforce size but lacks context unless tied to performance expectations. The number of vacation days taken indicates employee behavior but does not directly correlate with organizational performance. The cost of office supplies, while representational of operational efficiency, does not measure workforce effectiveness or culture directly. Thus, focusing on the employee turnover rate allows organizations to take informed actions based on its impact on overall performance.