Exploring the Structure of Complex Software Designs: An Empirical Study of Open Source and Proprietary Code

This paper reports data from a study that seeks to characterize the differences in design structure between complex software products. We use design structure matrices (DSMs) to map dependencies between the elements of a design and define metrics that allow us to compare the structures of different designs. We use these metrics to compare the architectures of two software products—the Linux operating system and the Mozilla Web browser—that were developed via contrasting modes of organization: specifically, open source versus proprietary development. We then track the evolution of Mozilla, paying attention to a purposeful “redesign” effort undertaken with the intention of making the product more “modular.” We…

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  Carnegie Mellon University