David Dreyfus

Enterprise Architecture: A Social Network Perspective

IS Architecture emerges as a result of a sequence of IS project implementations. The architecture that emerges can be viewed as a network of software components linked by their interdependencies. The network influences, and is influenced by, the intra-organizational interdependencies in which it is embedded. IT management can influence the evolution of the network, and, by extension, the evolution of the organization. However, given time and cost constraints, IT management can most directly influence only a few of the components in the network, the architectural control points. In this research we show how a network perspective using research from social network analysis provides a useful abstraction for understanding architecture. We apply modular operators from design theory to enact changes to architecture. Finally, we show that by following a few simple rules, enterprises can improve the fitness of their architecture as the network emerges and the control points shift over time.

Managing architectural emergence: A conceptual model and simulation

Information systems are increasingly interconnected. They evolve through a sequence of projects that are affected by, and subsequently modify, this interconnectedness. We suggest that decision makers can influence emergent information systems by closely managing only a subset of their applications. We define this set of applications as the architectural control points (ACPs). To help architects manage their architecture, we develop a conceptual model of information system architecture as a network comprising a set of nodes linked by dependencies. We use simulation and network analysis to identify and show the value of ACPs.

Visualizing and Measuring Enterprise Architecture: An Exploratory BioPharma Case

We test a method that was designed and used previously to reveal the hidden internal architectural structure of software systems. The focus of this paper is to test if it can also uncover new facts about the components and their relationships in an enterprise architecture, i.e., if the method can reveal the hidden external structure between architectural components. Our test uses data from a biopharmaceutical company. In total, we analyzed 407 components and 1,157 dependencies. Results show that the enterprise structure can be classified as a core-periphery architecture with a propagation cost of 23%, core size of 32%, and architecture flow through of 67%. We also found that business components can be classified as control elements, infrastructure components as shared, and software applications as belonging to the core. These findings suggest that the method could be effective in uncovering the hidden structure of an enterprise architecture.

Visualizing and Measuring Software Portfolio Architecture: A Flexibility Analysis

In this paper, we test a Design Structure Matrix (DSM) based method for visualizing and measuring software portfolio architectures, and use our measures to predict the costs of architectural change ...

Competing in the Era of Emergent Architecture: The Case of Packaged Software Industry

The firms that comprise the prepackaged software industry form a complex system engaged in systems-based competition. This complex system survives and grows because it follows emergent design principles notably articulated by Herbert Simon. In particular, complex systems form stable subsystems -clusters - that can be described (in this industry) as a stack. In this research, we study the evolution of the software industry using data on packaged software development firms over 13 years (1990-2002) across functional markets. We show that by exploiting complementarities based on the emergent architecture, firms can outperform competitors that use complementarities that are based on the espoused architecture/stack, which outperform those that ignore architecture altogether