Scalability has often been a term used to describe a Web-based application’s ability to handle increased load after additional hardware has been added to the infrastructure. Web-based applications are considered "scalable" when they have the ability to increase total throughput under an increased user load after additional hardware has been added. As software has evolved beyond the desktop to a server-based delivery model, application scalability has become a key element to high-quality software designs. For Web-based server applications, scalability considerations such as hardware infrastructure design, load balancing, deployment, and application manageability have a direct influence on both the application design and the cost associated with scaling to meet user demands. To ensure that Web-based applications can scale effectively to accommodate increased user load, scale factors should always be considered as part of the application design. By doing so, application developers can help to mitigate post-release quality or application health issues discovered under heavy load.