Discussion and Limitations
The critical synthesis of current scholarship highlights a structural transition from perimeter-centric defenses to quantifiable assurance in industrial cloud settings. Establishing verifiable maturity metrics addresses the persistent governance, risk, and compliance challenges inherent to complex multi-cloud deployments ("Quantifying Zero Trust: Developing GRC Metrics for Mature Cloud Environments," 2022). Simultaneously, embedding zero-trust paradigms within distributed industrial networks mitigates lateral movement and strengthens access controls across operational domains ("Implementing Zero Trust Architecture to Secure IIoT in Hybrid Cloud Environments," 2026). However, existing maturity models exhibit a pronounced research gap by focusing predominantly on static governance checklists rather than real-time telemetry verification across heterogeneous industrial assets. Furthermore, dynamic anomaly detection mechanisms often encounter trade-offs in precision, underscoring the demand for more intelligent verification mechanisms that actively filter sophisticated attacks within distributed infrastructures ("Federated Learning and Zero Trust Framework for Anomaly Detection in Distributed IIoT-Cloud Systems," 2026). Integrating legacy field devices with cloud-native identity planes introduces severe operational friction, as hardware constraints and strict latency thresholds limit the direct enforcement of continuous authentication. This study is subject to several analytical limitations. First, the assessment framework relies on standard architectural abstractions, which may obscure vendor-specific protocol incompatibilities in proprietary operational technology networks. Second, the absence of longitudinal data across varying enterprise tiers restricts the evaluation of organizational cultural resistance and multi-cloud operational overhead during incremental zero-trust adoption. Addressing these systemic constraints requires future inquiry into autonomous compliance telemetry and interoperable identity standards for distributed industrial ecosystems.