In Systems engineering and Requirements engineering, a Non-Functional Requirement (NFR) is a requirement that specifies criteria that can be used to judge the operation of a system, rather than specific behaviours. Previously this would be mainly Architecture of the system. For example: Scalability, Accessibility, Capacity. These are all still important, however, it should be about more than this in a SaaS world!

Why do I think this is far more important then ever to get right? From an Architecture perspective, you need to get this right or you will have heavy costs fixing issues in the future. But more importantly you should be setting out to the business what are your expectations of the overall customer experience. You have to remember that software is not a solution on its own, everything from the purchasing journey to the training journey and how you are going to support your customers, are also part of the overall solution, and getting this right will retain customer loyalty.

When thinking of your NFR, think about the experience you want your customers to have and draw out all these journeys, so that every area of the business is aware of their responsibility.  Some questions to ask are:

• Are we going to offer free trials? If so, how are we going to support them? What do we need from development, sales, pre-sales, marketing?
• What is the work flow for customers to purchase? Do we have Account Managers selling? Are we expecting customers to purchase from a portal? Who across the business needs to be involved?
• Are we going to do all training online? Will this be self service? Do we have partners who need to train the software? Are we going to sell the environments?  Who across the business needs to be involved?
• How are we going to support our customers, once they are trained and on-board?

There are many more questions, but all of them will have a potential impact on the overall solution (incl. Architecture) and customer satisfaction. Once you have been through this exercise, most NFRs will be the same for subsequent solutions. But always review the NFRs and learn how you can make the solution better.