Most of the researcher I found that they use productivity index. They used total output/ total input. What else can be the solution for assessing the productivity of the workers.
First of all, you should find out about the exact definition of labor productivity. You can then obtain further important information from the following source:
One common method is to use time and motion studies. This involves observing workers as they perform their tasks and recording the time it takes them to complete each task. This information can then be used to identify areas where productivity can be improved.
Another method is to use performance metrics such as output per worker or output per hour. This can help identify areas where workers are underperforming and help managers develop strategies to improve productivity.
One way is to measure the output of workers over a period of time and compare it to the input (resources) used to produce that output. This can be done by determining the input, determining the output, applying the formula and comparing it to the baseline.