Mission-critical applications, such as real-time emergency response, healthcare, and transport systems, depend heavily on the low latency and reliability provided by Mobile Edge Computing (MEC). The failure of such applications can lead to high latency and severe consequences, including loss of life, financial catastrophe, or operational disruption. However, the dependability of edge clusters is often overlooked, particularly in terms of fault awareness and recovery strategies, which are crucial to these applications. In this work, we focus on loosely coupled IoT applications and propose a Failure and Latency-aware Scheduling approach for Edge (FaLSE) that balances the trade-off between the availability of edge clusters and the latency of containerized mission-critical applications. We used a decentralized network coordinate system to estimate latency between IoT devices/users and nodes. To validate the proposed approach, we compare it with the standard Kubernetes scheduler, which is currently among the most widely used workload orchestration platforms. The results indicate that FaLSE reduced the failure request rate by 87.9% while maintaining a 71.97% lower 95th percentile latency for mission-critical applications and a 10.63% lower latency for normal applications compared to the standard Kubernetes scheduler.