Software Constraints

Definition

A software constraint is a constraint that constrains the architecture, design, implementation, or testing of a software component.

Objectives

The typical objectives of a software constraint are to:

• Ensure that some or all software components conform to necessary architecture, design, implementation, and testing constraints that have been imposed for business or technical reasons.

Examples

The following are typical examples of software constraints:

• Architecture Constraint:
  “The application shall use a layered architecture, whereby each layer may only access the layer directly below it.”
• Design Constraint:
  “All application software shall be modularized into classes using object-oriented design principles.”
• Implementation Constraints:
  • “To the extent that it is practical, all software components of the application shall be programmed in the Java programming language.“
  • “All Java software components shall conform to the official organizational Java programming standards.“
• Testing Constraint:
  “The component shall include built-in self-test software that automatically and continuously tests the component while it is in operation.”

Guidelines

The following guidelines have been found to be useful when producing software constraints:

• Do not unnecessarily constrain the architecture, design, or implementation of software components.
• Some software constraints can be specified via programming standards.