To support engineers in solving engineering problems utilizing digital twin, we are proposing 'digital triplet' concept. We are also developing a problem-solving process support method by using the Log Level Description (LLD) that describes an executed problem-solving process and the Generic Process Model (GPM) that describes a generalized and prescriptive process. This paper illustrates a support method for describing LLDs to put the proposed method into practical use. Through an attempt to describe LLDs, three time-consuming operations were identified: viz., interviewing, structuring the information, and relating each action with the GPM. To save the labor of these operations, we propose the method that the engineer who executes the process sequentially describes the LLD by oneself based on the GPM. This paper also illustrates an LLD description support system based on the proposed method. Finally, a case study was conducted to describe the actual fault detection system design processes with the developed support system. By comparing the LLDs created with the support system in the case study with the ones created manually, the effectiveness of the proposed method was discussed. In addition, by interviewing engineers who created the LLDs in the case study, the usefulness and feasibility of the proposed method were discussed.