This paper is about the development of problem solving method to identify failures in inconel 718 mainly applied in the subsea environment. A3 analysis with support from fishbone diagram and 5 whys analysis techniques were introduced to identify the actual cause of failures. Upon identification of the actual cause of failure, improvement actions were taken to eliminate the actual cause. In this research, the identification of the actual cause of failure related with the Inconel 718 fasteners that were used for Methanol Injection Tree Valve (MITV) was performed. Lab analysis on fresh and failure fasteners was performed by comparing the mechanical properties, chemical composition and microstructure analysis. The data was then compared to understand the characteristics of the failure. Future state and target in A3 stage required a mitigation action to eliminate the cause of failure. This was performed by conducting new material analysis i.e. L7M fasteners for future reference. Standard template for subsea's problem solving method was established upon completion the analysis for future use.