A Model of Configuration Complexity and Its Application to a Change Management System

The complexity of configuring computing systems is a major impediment to the adoption of new information technology (IT) products and greatly increases the cost of IT services. This paper develops a model of configuration complexity and demonstrates its value for a change management system. The model represents systems as a set of nested containers with configuration controls. From this representation, we derive various metrics that indicate configuration complexity, including execution complexity, parameter complexity, and memory complexity. We apply this model to a J2EE-based enterprise application and its associated middleware stack to assess the complexity of the manual configuration process for this application. We then show how an automated change management system can greatly reduce configuration complexity.