The most effective tool to determine the best asset of an employee is an actual work performance evaluation.
Experience and educational qualifications are assets modified by companies in defining the asset of an employee but due to my personal observation, these are not enough and what we need is an actual evaluation/assessment while the employee is actually carrying the tasks.
While working, the quality and effectiveness of work provided by experience, the manner drawn from the education show as PROOF. Only through actual performance an employee can prove his best asset and only through this way a company can determine an employee.
There are two types of evaluation of employee performance; The probation period for the new employee and the periodic evaluation period for the old employees.
Once you were able to determine the asset of a particular employee, you will be able to know his weakness as well, as a Manager, how will you deal with this situation? Will you focus and enhance his ability or will you establish a training course to improve his weakness?
