There are different views on an information system, and one of them is a look of the architect of information systems. The analyst thinks over the system meet the customer requirements functionally. But there is a difference between a system that does what is necessary and a system that satisfies the customer expectations. The task of the architect – to make the system fulfilling the customer completely. The talk reveals a row of characteristics of quality of information systems and shows how the quality assurance can influent on the system functional requirements.