Hidden dependencies in program comprehension and change propagation

Large software systems are difficult to understand and maintain. Program dependency analysis plays a key role in both understanding and maintenance. This paper discusses hidden dependencies among software components that make both understanding and maintenance hard. A hidden dependency is a relationship between two seemingly independent components, and it is caused by the data flow in a third software component. The paper uses abstract system dependency graphs to define hidden dependencies. It discusses the impact of hidden dependencies on the process of change propagation and also discusses an algorithm that warns about the possible presence of hidden dependencies