Scalability Guidelines for Software as a Service: Recommendations based on a case analysis of Quinyx FlexForce AB and UCMS Group Ltd.

Abstract: Software as a service (SaaS) has become a common business model for application providers. However, this success has lead to scalability issues for service providers. Their user base and processing needs can grow rapidly and it is not always clear how a SaaS provider should optimally scale their service. This thesis summarizes the technological (both software and hardware) related solutions to scaling, but will also cover financial and managerial aspects of scalability. Unfortunately, there is no existing out of the box solution for managing scalability, every situation and application is currently viewed as a unique problem, but there exists a lot of good advice from many sources about scaling. Obviously there are practical solutions to scaling, as there are successful SaaS providers, but it is not clear if there exists some fundamental principles that every SaaS provider could use to address the issue of scalability. This thesis seeks to find such fundamental principles though previous research, articles and finally a case analysis of Quinyx FlexForce AB. The thesis concludes that there are many principles of scaling a 3-tier web system and that most principles can be applied by SaaS providers.