Efficiency

Definition

Efficiency

the quality factor representing the degree to which an application or component effectively uses (i.e., minimizes its consumption of) its resources

Classification

As illustrated in the preceding figure, Efficiency is part of the following inheritance hierarchy:

• Type: Concrete
• Superclass: Quality Factor
• Subclasses:
  • Bandwidth efficiency,
    which is the efficiency of the network
  • Processing efficiency,
    which is the efficiency of the processors
  • Storage efficiency,
    which is the efficiency of the memory
  • Power Effeciency

Responsibilities

The typical responsibilities of Efficiency are to:

• Model how effectively resources are being utilized.
• Support the analysis and specification of efficiency requirements.
• Provide a foundation for evaluating the quality of an architecture.

Subfactors

Efficiency is typically decomposed into the following aggregation hierarchy of subfactors:

• TBD

Measures

Efficiency is typically measured in terms of the:

• Amount of memory
• CPU cycles
• Network bandwidth
• Facilities expense
• Personnel hours

Mechanisms

Typical mechanisms for implementing efficiency include:

• TBD

Guidelines

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

• Efficiency may include all types of resources such as computing (hardware, software, and network), machinery, facilities, and personnel.
• 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.