Stop Allocating, Start Coordinating: Graph-Based Functional Modeling of Human-Machine Architectures

To achieve graceful extensibility, system architectures must support human-machine coordination. This paper operationalizes a coordination-first design approach through the Joint Strategies Analysis Toolkit (JSAT), a graph-based functional modeling framework. To overcome the challenges associated with the “envisioning stage” of designing new machine capabilities, JSAT employs a recursive bootstrapping methodology that uses functional models to develop hypotheses about how humans and machines could coordinate. Using a disaster response scenario, we demonstrate how JSAT maps core operational functions alongside the coordination required to support system extensibility. By analyzing the resulting directed graphs with structural metrics like feedback cycles and shared authority, JSAT equips designers to generate hypotheses regarding potential coordination bottlenecks, anticipate authority-responsibility mismatches, explore design trade-offs, and ultimately develop well-integrated human-machine systems.