Relating the evolution of design patterns and crosscutting concerns

Crosscutting concerns consist in software system features having the implementation spread across modules as tangled and scattered code. In many cases, these crosscutting concerns represent design pattern clients, i.e., invocations to pattern features. When a design pattern evolves, this can cause the addition or the change of scattered and tangled code, which contributes to the evolution of the crosscutting concern. This paper empirically analyzes the relationship between design pattern evolution and the changes in the induced crosscutting concerns. Specifically, the paper investigates to what extent the crosscutting concern co-changes with the pattern, whether there is a relationship between the type of change and the induced crosscutting change, and whether different patterns induce different amount of crosscutting. The paper reports results from the analysis of Tomcat and JHotDraw evolution.