Efficiency Requirements

Definition

An efficiency requirement is a user-oriented quality requirement that specifies a required amount of efficiency, which is a quality factor that is defined as follows:

Efficiency

the degree to which something effectively uses (i.e., minimizes its consumption of) its computing and personnel resources.

Objectives

The typical objectives of a efficiency requirement are to:

• Minimize its need for computing resources:
  • Processors.
  • Memory.
  • Mass storage.
  • Communication networks (e.g., bandwidth).
• Minimize its need for personnel resources:
  • Operations organization.
  • User support organization.

Measurements

Efficiency requirements are typically specified in terms of the following measurements:

• TBD.

Examples

The following are typical examples of efficiency requirements:

• “The client part of the application shall not require more than the following computing resources:
  • A Pentium II processor (or the equivalent).
  • 64 meg of RAM.
  • 80 meg of hard drive.
  • A 56K modem.”

Guidelines

The following guidelines have been found to be useful when producing efficiency requirements:

• The scope of an efficiency requirement can be:
  • A business enterprise
  • An application
  • A component
  • A center
• Avoid ambiguous efficiency requirements that are therefore not validatable such as:
  “The application shall minimize its use of computational resources.”
• Typically, efficiency is inversely related to accuracy, maintainability, portability, and understandability.