What are the most common quality attributes and metrics for service-oriented and cloud-based requirements?

1 Quality attributes

Quality attributes, also known as ilities or non-functional requirements, are the non-functional characteristics of a system that affect its usability, reliability, efficiency, maintainability, and security. Common quality attributes for service-oriented and cloud-based systems include availability, scalability, interoperability, modularity, and testability. Availability measures the proportion of time a system is operational and accessible to users and clients. Scalability indicates the system’s ability to handle increasing or varying workloads without degrading performance or functionality. Interoperability refers to the ability of a system to exchange and use information with other systems or components. Modularity measures the degree to which a system is composed of independent and cohesive units that can be reused, replaced, or modified. Lastly, testability indicates how easy it is to verify and validate a system for correctness and quality.

3 Requirements elicitation

Requirements elicitation is the process of discovering, understanding, and documenting the needs and expectations of the stakeholders of a system. It is an essential step in requirements engineering, as it defines the scope and quality of the system. Interviews are a direct and interactive way of obtaining information from stakeholders by asking questions. Surveys are a structured and scalable way of collecting data from multiple stakeholders with predefined questions or rating scales. Workshops offer a collaborative and creative approach to generate ideas or solutions from stakeholders through brainstorming, prototyping, or prioritization methods. Observation is an indirect and empirical way of understanding the context and behavior of stakeholders by watching them perform their tasks or use existing systems. Lastly, document analysis is a systematic and analytical technique for extracting information from existing sources, such as reports, specifications, or standards.

4 Requirements specification

Requirements specification is the process of defining, organizing, and documenting the requirements of a system in a clear, consistent, and verifiable way. It is an essential step in requirements engineering as it communicates the requirements to the developers, testers, and managers of the system. There are several formats for requirements specification for service-oriented and cloud-based systems, such as use cases - a textual or graphical description of the interactions between a system and its actors to achieve a specific goal - or user stories - a concise and informal statement of a user's need or desire from a system. Furthermore, service contracts provide a formal and precise definition of the interface, behavior, and quality of a service, usually expressed in XML or JSON. Lastly, models are visual or mathematical representations of the structure, behavior, or data of a system using notations like UML or BPMN.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?