Advocates of software engineering and software project management stated in the literature that creeping of scope is one of the most common causes for the failure of software projects. Also, advocates believed that it could occur in almost every software project, which leads to compromise in quality, delayed schedules, increase cost and decreased customer satisfaction. However, the lack of empirical evidence demands a comprehensive investigation to identify the factors of scope creep and to propose a conceptual framework to empirically evaluate the impact of scope creep on software project success. To determine the scope creep factors in this study, two exploratory methods, i.e. a Systematic Literature Review (SLR) and interview from experts are performed. Following the analysis of these methods, a conceptual framework is proposed. To empirically evaluate the proposed conceptual framework, data is collected through a survey method. Next, the collected data is analyzed through Partial Least Squares' Structural Equation Modelling (PLS-SEM). From the results, it is evident that the identified factors of scope creep are negatively associated with software project success. The results of empirical evaluation also second the findings of SLR. The outcome of the study may help the practitioners to understand the dynamics of factors, which undermine scope creep in software SMEs and to assist them in the development of effective control and mitigation strategies, therefore, to increase the project success rate. INDEX TERMS Scope management, scope creep, requirement creep, software project success, partial least squares structural equation modeling.