TY - JOUR AU - Momani, Shaher AU - Jebril, Iqbal H. AU - Batiha, Iqbal M. AU - Calucag, Lina S. AU - Biswas, Anjan PY - 2026 TI - Analyzing finite-time convergence for variable-order fractional discrete dynamics in Degn–Harrison reaction–diffusion systems JO - AIMS Mathematics SP - 12204 EP - 12232 VL - 11 IS - 4 AB - This study presents a novel investigation into finite-time stability (FTS) and synchronization phenomena within a discrete reaction–diffusion system (RDS) governed by variable-order fractional (VOF) operators, inspired by the Degn–Harrison (D–H) model. By employing Caputo-type VOF differences, we model memory effects and time-varying dynamics typical of complex biological and chemical processes. Theoretical contributions include rigorous Lyapunov function (LF)-based criteria for establishing tempered Mittag-Leffler stability (MLS) and global FTS, as well as explicit expressions for the settling time T ∗ . A fractional-order (FO) error system is also analyzed, demonstrating that linear coupling ensures finite-time synchronization under variable-order conditions. Extensive numerical simulations confirm the theoretical predictions across various FO profiles δ ( t ) and parameter regimes. These findings bridge discrete fractional modeling with practical control strategies for systems exhibiting hereditary and anomalous diffusion effects. UR - https://doi.org/10.3934/math.2026501 DO - 10.3934/math.2026501