In recent years, the cloud hype has resulted in numerous offerings across the cloud market, including Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS). Despite their popularity, several issues persist, particularly regarding PaaS, where the diverse provider landscape complicates application portability assessment. This thesis focuses on analyzing and improving application portability in PaaS environments, examining obstacles throughout an application's life cycle—from selecting a suitable cloud provider to deployment and operation. It introduces a decision support system designed to help users select cloud platforms that facilitate application portability through an enhanced conceptualization of PaaS. A case study involving the migration of a real-world application across different cloud platforms validates this system. Additionally, an assessment framework is developed to quantify migration efforts, highlighting the application management interface as a key factor in migration challenges. To mitigate this effort, a unified interface for application deployment and management is proposed. Overall, the work identifies application portability issues in PaaS environments and offers a framework for early detection and avoidance, contributing to reduced lock-in effects through a standardized management interface.
