It is synonymous with ability. A person gains competency through education, training, experience, or natural abilities. These KSAs must distinguish between superior and other performers. Conversely, performance is the accomplishment of a task in accordance with a set standard of completeness and accuracy. In other words, competencies give a person the ability to perform, while attitudes give a person the desire to perform.
Attitudes change with various events in a person's life.
These emotional changes also vary in length of time. My performance appraisal is due in four weeks. My performance increases in the hope that I will get a better review. I am deeply in debt and my performance drops as this burden weighs heavily upon my mind. One task is very complex and takes up the majority of my time.