Skip to main content

Features and Requirements

This section breaks down what the system will do and how it will perform. It is divided into three main categories: Features, which are high-level descriptions of services the system provides, Functional Requirements, which are the specific, detailed statements of what the system must do, and Non-Functional Requirements, which define how the system should perform.

Features​

A feature is a distinct piece of functionality that provides value to a user. Features are described from a user's perspective and answer the question, "What can I do with this system?"

For example, in a photo-sharing app, features might include:

  • User Authentication (Log in, Log out, Register)
  • Photo Uploading
  • Creating Albums
  • Sharing Photos with Friends

Functional Requirements​

Functional Requirements define the specific behaviors, functions, and responses of the system. They are the detailed specifications of the features. Each feature is typically broken down into one or more functional requirements. These requirements should be specific, measurable, and testable.

Following the "Photo Uploading" feature example, the functional requirements might be:

  • REQ-1.1: The system shall allow a user to select one or more image files from their local device.
  • REQ-1.2: The system shall support .jpg, .png, and .gif image formats.
  • REQ-1.3: The system shall display a progress bar during the upload process.
  • REQ-1.4: The system shall confirm successful upload with a message to the user.
  • REQ-1.5: The system shall display an error message if the upload fails.

Non-Functional Requirements​

While Functional Requirements define what the system does, Non-Functional Requirements (NFRs) define how the system should perform its functions. They specify the quality attributes and overall characteristics of the system, which are crucial for ensuring it is usable, reliable, and maintainable.

This section should cover areas such as:

  • Performance: How fast the system responds to user actions (e.g., response time, throughput, resource usage). For example, "The user dashboard shall load in under 2 seconds."
  • Scalability: The system's ability to handle a growing amount of work. For example, "The system must support 1,000 concurrent users without a degradation in performance."
  • Reliability: The system's ability to perform its required functions under stated conditions for a specified period. For example, "The system shall have 99.9% uptime."
  • Security: The measures in place to protect the system and its data. For example, "All user passwords must be hashed and salted."
  • Usability: The ease with which users can learn and use the system. For example, "A new user should be able to complete the registration process in under 3 minutes."
  • Maintainability: The ease with which the system can be modified. For example, "The codebase must adhere to the specified coding standards."
  • Portability: The ability of the software to be transferred from one environment to another. For example, "The application must be able to run on both Windows and Linux servers."