The three factors are as follows (Jha, 2011); (1) Overload factor; this factor shows that the human's load and abilities are incompatible, resulting in nervousness, stress, lethargy and feelings that can be exaggerated by physical environments such as dust, light, noise , fumes and many other physical stimulations in the work environment. (2) Incorrect answer; which produce by a person caused by the incompatible situation in which he works. (3) Inappropriate activity; which occur either due to a lack of knowledge in performing the task or deliberately