Software as a service is software sold as a subscription and used in a browser. Building one is a business decision before it is a technical one.
What makes it SaaS
Customers sign up, use the product online and pay regularly. You run the servers, fix the problems and keep improving it for everyone at once.
Questions to answer first
Answer these before you spend on a build.
- Who is the customer, and do you know ten of them?
- What painful problem does it solve today?
- Why would they pay rather than use a spreadsheet?
- How will you reach the first hundred customers?
Plan for running it
A SaaS product needs support, security, backups and updates every month for as long as customers use it. Budget for that, not only for the build.