LITERATURE REVIEW 5 4.1 Definitions of Key Concepts 6 4.1.1 Customer Retention 6 4.1.2 Corporate Image 6 4.1.3 Quality 6 4.1.4 Project Management 7 4.1.5 Relationship with the Customer 7 4.2 Critical Review of Theories and Models Regarding Factors that Influence Customer Retention 7 4.2.1 Theories Regarding Customer Retention 8 4.2.2 Assimilation-Contrast Theory 8 4.2.3 Theory of Negativity 8 4.2.4 Cognitive Dissonance Theory 8 4.2.5 Review of Models Regarding