Human dimension plays a critical role in determining budget outcomes. The managers performance in budget setting will indicates the extent of the organizational success. As budget represent the important tool in translating the planned strategies into action, it is therefore critical for the managers to adapt the correct behavior that could significantly shape and lead them into good performance. This paper presents the examination of the ‘Trail Model’ in determining a manager’s performance in budget setting. The model suggest that managers performance is improved by influential factor of and the integration effect of human dimension of fairness, commitment and satisfaction with budget performance. The dimension of fairness, which is represented by procedural fairness is investigated. The result of the study on 128 budget managers in mechanistic public organization via survey questionnaire found to be favorable, positive and significant. The paper suggests the usefulness of Trail Model as behavioral guidance instrument of human dimension in budget setting.