I received a phone call today from a friend who was very upset after receiving her paycheck. She had been working hard toward a performance bonus but nothing was reflected in the amount she received. After questioning her boss, she found out that the measurement criteria had been changed. Rather than take the total of the three months in the quarter, management decided to take an average of the three months. This change was significant enough that it caused my friend to miss the target. She acknowledges that it is up to management to set the objectives and to change them at will, however, she felt very betrayed that the changes were not communicated in advance. When setting performance targets of any type it is crucial to clearly communicate the criteria that will be used and if business needs dictate a change to the criteria, this should also be clearly communicated in a timely fashion. After all, the purpose of creating performance bonuses is to foster the behavior  that will help the organization achieve it's objectives. It should be a win-win for the company and the employee. When employees encounter targets that they feel are unreasonable or unachievable, they stop trying.