Answer:
1) Key Performance Indicators (KPIs)
2) Covers per hour
Explanation:
Critical success factors (CSFs) are fundamental requirements for competitive success. They represent what a business must excel at to make it very competitive and successful.
For example, customer satisfaction, quality product, employee satisfaction, productivity
Key Performance Indicators (KPI) are metrics  which are used to measure whether or a business is achieving its CSFs
For example, a measure (KPI) of employee productivity would be amount of covers achieved per hour of labour