An important issue during architectural design is that besides functional requirements, software architecture is influenced greatly by quality requirements, which often are neglected. The earlier quality requirements are considered, the less effort is needed later in the software lifecycle to ensure a sufficient software quality levels. Errors due to lack of their fulfilment are the most expensive and difficult to correct. Therefore, attention to quality requirements is crucial during an architectural design. The problem is not only to gather the system's quality requirements, but to...