The theory says that the degree of motivation derives mainly from the employees themselves and from the reference object from the proportion of harvest and subjective feeling. And the theory is a study of the relationship between man's motivation and his perceptions. Adams's book Managing Employee Performance and Reward (Adams 1965) focuses on the rationality and fairness of wage distribution and the effect of the quality of work enthusiasm on workers' output. When employees achieved results and were paid, they were not only concerned with the absolute amount of their income, but also with the relative amount of the work performed. To determine whether the reward is reasonable, several comparisons need to be made, and the results of the comparison will directly influence future enthusiasm. Additionally, regardless of position, employees who want to feel that their contributions and performance are rewarded and are paid. If employees feel less paid, this will lead to a feeling of hostility towards the organization or perhaps their colleagues and could result in poor employee performance at work. It is a subtle variable, which also had a fair sense of important role. It's just an idea that honors job performance and appreciates employees that creates a sense of satisfaction that helps employees feel good and translates into simple behaviors. Criticisms have emphasized both the practical application of the hypotheses and the equity theory. Critics also argue that one might think of equity or inequality not only in relation to specific inputs and outcomes, but also in terms of determining the overall system of those inputs and outputs. Therefore, in a corporate environment, one may believe that one's pay is fair compared to other employees, but we may view the entire pay system as unfair (Carrell and Dietrich, 1978, p..