This paper proposes Temporal Optimization (TempOpt), a novel unsupervised learning technique for effectively analyzing the massive volume of fault alarms generated in network operations centers (NOCs) in telecommunication networks and identifying their root causes. It overcomes the limitations of existing temporal dependency methods by learning relationships between alarms. Experiments using a real-world network dataset demonstrate improved alarm relationship learning performance compared to existing methods. This can contribute to the rapid and accurate resolution of network faults.