It is very interesting to be an employer and employee at the same time. On one hand, I am not happy about the performance of my currnt employee while I sometimes fail to accomplish the task required by my superior. 
The understanding between the two sides of employment is critical. As a boss, he or she needs to know sometimes the employee has some ceiling of ability, or time schedule that may not allow such employee to finish the task in time, etc. etc. As an employee, he or sh needs to take on the pressure of work and tackle the pressure by well arrange all tasks in good order and finish in a diligent manner.