Ecommerce Performance As A Non-Functional Requirement
When gathering the business requirements for an new ecommerce site project or replatform it's common to focus on the functional requirements but non-functional requirements are just as important. A commonly overlooked but vital non-functional requirement for enterprise sized ecommerce websites is performance. Performance in terms of how many visitors, page views, sessions, orders or whatever KPIs are likely to place restrictions on how far the business can grow. There are different ways to define performance and being tight with the definition is important as a UAT (User Acceptance Testing) criteria. For example, if the performance metric is how many pages can be served per second then the definition must take into account AJAX requests and the kind of pages being served. It's a good practice to created a profile of the number of product pages, product list pages, basket views, add to baskets, search results, payment entry, etc. pages so that performance can be measured on the new site using an upfront agreed performance testing method.