Revisit the System Requirements

Before you begin the design process, you must ensure that you have a complete set of system requirements. If the system requirements were defined by another individual or group, you should review the requirements and then walk through your understanding of them with the group and ideally the stakeholder who served as the expert for the requirements specification. Identifying errors, omissions, and misunderstandings early in the design process will save considerable time and money later.

System requirements fall into one of two categories: functional requirements and nonfunctional requirements. The functional requirements specify what the system does—that is, the specific tasks the system will perform. Normally, the functional requirements are provided by the system or business analyst to the designer within the specification of the things that the system needs to do. In contrast, nonfunctional requirements specify how the system will work behind the scenes. Nonfunctional requirements are often called quality requirements and include common factors such as performance, reliability, maintainability, and so forth. As a designer with a strong working knowledge of the cloud environment, you can exhibit considerable influence on the system’s design to meet the nonfunctional requirements. Much of this chapter examines specific design considerations for nonfunctional requirements.

As you identify system requirements, you should establish benchmarks you can use throughout the design and implementation to ensure your solutions satisfies each requirement. A simple benchmark, for example, is that all screens will render within 3 seconds following a user interaction.