Abstract. Current solutions for fault-tolerance in HPC systems focus on dealing with the result of a failure. However, most are unable to handle runtime system configuration changes caused by transient failures and require a complete restart of the entire machine. The recently released HA-OSCAR software stack is one such effort making inroads here. This paper discusses detailed solutions for the high-availability and serviceability enhancement of clusters by HAOSCAR via multi-head-node failover and a service level fault tolerance mechanism. Our solution employs self-configuration and introduces Adaptive Self Healing (ASH) techniques. HA-OSCAR availability improvement analysis was also conducted with various sensitivity factors. Finally, the paper also entails the details of the system layering strategy, dependability modeling, and analysis of an actual experimental system by a Petri net-based model, Stochastic Reword Net (SRN).