The subject of assessment can be a wide spectrum of qualities of employees: features of behavior, professional competences, personal and intellectual traits.
The basic purpose of personnel assessment is obtaining information for making decisions concerning certain employees of the organization.
Such decisions as hiring, promotion, rotation, discharge, rewarding, punishment, development of a training program require the assessment of what this or that employee can, wants, what level of professionalism he (she) has reached, what kind of professional problems he (she) has, whether he (she) has potential of development in this or that direction.
In a sense, any manager is involved in some kind of assessment activity. It is inevitable. The thing is that for the assessment to be correct and objective, special methods and instruments are necessary.
The result of assessment is not only a general characteristics of an employee, but also his (her) "risk factors" (undesirable traits for the particular activity which can lead to failures in work) and "success factors" (the qualities helping in achievement high results in work).