This paper evaluates scalability in Platform as a Service (PaaS) within cloud computing, proposing a Scalability Improvement System (SIS) that utilizes caching to enhance performance and scalability. It discusses the challenges of scalability testing and presents a graphical model for implementing SIS, which incorporates load balancing and caching strategies to improve resource management. The study concludes that SIS effectively enhances scalability while reducing operational costs and response times.