Managing change with patterns

Costs associated with modifying software are a large part of an organization´s software development budget. Since change is to be expected, the costs associated with change can be reduced by preparing for it. Software design patterns associate a problem and context with a solution to document good design practices. Patterns allow software designers to evaluate solutions in terms of the aspects of the system most likely to vary. This article uses the INgage^TM Intelligent Peripheral Prototype to demonstrate how the use of two patterns, Layers and Mediator, facilitated a major change to the protocol stacks, and isolated object interactions to make them more maintainable