Grid-Based Functional Feasible Domain for Regional Decision-Consequence Assessment in Heterogeneous Multi-UAV Systems

Resource assignment in heterogeneous multi-UAV systems changes both current task outcomes and the task chains that remain feasible across a mission region. Completion, delay, utilization, and role-specific reachability metrics do not retain this spatially resolved option space. This paper proposes the grid-based functional feasible domain (G-FFD), which represents capability- and time-constrained sensing–execution UAV chains subject to an intermediate decision/communication delay. A generalized index aggregates profile-labeled feasible chains and recovers feasible-chain count as the single-profile, unit-weight case. Shared resources and chain overlap describe functional coupling between grids. Controlled simulations show that local task bursts remove alternatives from external grids, with realized loss depending on the candidate-domain size, coupling, accepted demand, and occupied resources. Across 5 × 5, 10 × 10, and 20 × 20 grids, the high-G-FFD region has the largest mean peak external loss, although magnitudes and other regional rankings remain resolution-dependent. In a 20-seed paired stress test, G-FFD-guided selection reduces the cumulative external deficit relative to earliest-finish selection by a mean of 2.519 retention-minutes (bootstrap 95% confidence interval: 1.073–4.089). The differences in overall completion and post-burst completion of external medium/high-profile tasks remain inconclusive. G-FFD thus complements task outcomes with information about remaining regional alternatives and assignment consequences.