Modeling the microstructure and dynamics of complex technological systems

The discourse on the structure of technology and modularity typically focuses on the macro-level: Technology structures are modular if they limit the degree to which changes propagate throughout a complex system, constituted by how interdependencies among all parts pattern into a nested design structure with shared parts at the top transmitting functionalities via central parts down to the bottom.

In this talk, Sabine Brunswicker offers a complementary view and shifts the focus to micro-level structures of interdependencies that reflect the local decisions of designers with limited rationality. Such a micro- level view is particularly important given the rise of more distributed and digitally-mediated forms of organizing the design of technology. Today many complex technical systems are the result of parallel and iterative design efforts of a large number of actors. There is no “central designer”. Each designer engages in a purposive “local and situated” search for a technical solution for a design problem and makes choices related to the most fundamental types of micro-structures of interdependence, defined as a finite set of five distinct types of directed interdependencies between three parts. Brunswicker refers to these building blocks of modularity as design motifs, a term first introduced in biology. In her talk, she will present a design motif theory that builds upon the concept of design motifs to understand technology structures and sources of macro-level modularity. This theory assumes that value-seeking designers weigh costs and benefits when creating motifs. In a study, she and her co-authors empirically explore this design motif theory of technology structure using 20,000 different design structures of Nova, a cloud computing OSS product in Open Stack. They observe a stable, recurring design motif signature: High-value design motifs occur more frequently than low-value ones because of each motif’s idiosyncratic microstructure. The common resource motif occurs most frequently because of its low costs and its benefits for reliability in design. The sequential loop motif holds a critical role: It offers unique benefits for innovating system functionalities but when placed in the center it inflates the propagation of changes. This explains why central rather than shared parts are a potential source of innovation at the expense of modularity. Brunswicker will also present work-in-progress building upon this theory to explain the dynamics and evolution of complex technology structures by focusing on design motif transition over time. Such work will hopefully offer a new way to study technology evolution and scaling by specifically considering the microstructure of technologies.