Software as a Service (SaaS) has become one of the fastest-growing software business models in recent years. Even during the economic downturn following the pandemic, the SaaS business has emerged as a crucial model for IT companies. The revenue structure of SaaS, which is based on the subscription economy model, ensures that users pay only for the services used. In other words, SaaS operates on a subscription-based billing model, thus providing subscribers access to software uploaded to cloud computers via the Internet. This study aimed to explore the manner by which software-solution firms have to counteract the decline in profit and loss sales caused by changing their business-model orientation from on-premise deployment software to subscription-based software. Additionally it analyzes a method for selecting a subscription-based pricing model and rapidly recovering the investment costs via quantitative business-viability assessment. By calculating subscription fees via a more quantitative business-viability evaluation instead of focusing on conventional business-planning methods that rely on qualitative methods, companies are expected to be equipped in providing services to customers at reasonable costs. This strategy will facilitate them in leading emerging growth sectors.