The Information System functionality evaluation represents the procedure of assessing how successfully Information System fulfills its objectives. The process of evaluation includes synthesizing and determining gathered individual scores with the purpose of forming common opinion about the functionality of evaluated Information System. In the process of expressing general opinion professionals usually rely on their individual assessment abilities. Quality assessment and Information System ความผิดพลาดเพราะละเลยหรือไม่สังเกต is done with the purpose of organization’s Information System resources preservation and data integrity, in other words preservation of Information System functioning at the desired level of successfulness. The following may be regarded as the most important factors that influence the success of an information system: functionality of Information System; data quality; expected usefulness of Information System; expected usage simplicity of Information System; self-efficiency of Information System user; usage of Information System; influence of information system on individuals; Information System user’s satisfaction and organizational factors.