Subjective usually means either self ratings or supervisor ratings--objective usually means actual measures of results such as sales, defects, errors, output, profits, etc.
The practice of forced ranking merits consideration in discussions of objective and subjective evaluations of job performance. Forced ranking is a management tool that relies on annual evaluations to locate an organization’s best and worst performing personnel, using person-to-person comparisons. To improve the quality of the workforce, managers typically rank personnel against one another into three categories: the top 20% are “A” players who are expected to lead the organization in the future; the middle 70% are “B” players who are encouraged to improve; the bottom 10% are “C” players who are either offered training, encouraged to move elsewhere, or dismissed. Where it works, forced ranking loses its effectiveness after a couple of years because the average quality of personnel increases (else, the exercise is proved a failure) and there are fewer “C” players to identify. Critics have argued that forced ranking engenders a pseudo competitive environment conducive to patronage and yes-men; limited risk taking, creativity, and teamwork; as well as unethical (if not cutthroat) behavior that destroys trust in the workplace and depletes morale. It can also discourage workers from asking for help for fear they will be identified as low performers. Ironically, it can result in even good performers being cut if used on a yearly basis. A Primer on Talent Management, available at https://www.researchgate.net/publication/254583127_A_Primer_on_Talent_Management, touches on the issue of forced ranking in the context of more strategic and holistic efforts to make the most of critical human resources.
Job performance is the extent to which an employee has performed tasks, duties and responsibilities of his or her job during a certain period of time. Job performance can be classified as subjective job performance and objective job performance. Subjective means "difficult to define", "difficult to quantify", and "difficulty to verify" while objective means "easy to define", "easy to quantify", and "easy to verify". Generally following aspects ( which can be called as criteria that are factors of measuring success of the job performance) come under subjective job performance:
1. Quality of Work
2. Cooperation
3. Discipline
5. Planning, Organizing, Staffing, Directing and Controlling (in case of a managerial employee)
6. Cost Consciousness
7. Initiative
8. Creativity
9. Customer Treatment
10. Etc.
Generally following aspects come under objective job performance:
1. Quantity of Work
2. Attendance
3. Punctuality
4. Complaints
5. Praises
6. Recognitions
7. Number of Hours Served
8. Customers Served
9. Number of Innovations
10. Etc.
Two papers written by me which may be useful for you have been attached.