Chapter 8 Quality attributes and sizing of the dXp • Monitoring activities • Primary site monitoring • DR site monitoring • Metrics monitoring and notification Chapter Summary • The key quality attributes of a digital application are scalability, availability, performance, modularity, extensibility, and security. • Other quality attributes are usability, configurability, stability, interoperability, efficiency, flexibility, and maintainability. • Usability involves supports for various languages, contextual help, accessibility, friendly error messages, FAQs. • Security covers various aspects related to authentication, authorization, password policies, and such. • Reliability requires consistent performance of the application. • Scalability requirements are met if the application scales for increased user load and transaction load. • Availability requires continuous uptime and availability of the application. • Performance requirements cover application response time, process time, transaction completion time, and such. • Infrastructure sizing includes various factors such as load numbers, session numbers, content numbers, availability numbers, performance numbers, and throughput numbers. • A robust DR strategy includes DR planning, DR implementation, and DR maintenance. 233