## 1 Introduction  
Industry 4.0 is an industrial policy announced by the German government in 2011 [1]. It aims to reform the manufacturing industry by incorporating Information Technology (IT). The introduction of Industry 4.0 is a new way of using IT, such as Internet of Things (IoT) and big data analysis, to improve productivity efficiency and reduce the loss of raw materials, energy, and other resources. This will lead to increased efficiency in productivity and reduced loss of raw materials and energy. A similar evolution is occurring in asset management, which is called Maintenance 4.0. Maintenance 4.0 aims to digitize the maintenance process and automate the process of predicting and repairing equipment failures. However, even if Industry 4.0 and Maintenance 4.0 are introduced, their effects cannot be maximised if the Information and Communication Technology operating environment, which is the basis of technological innovation, is not in place. The manufacturing industry accounts for 20.6% of Japan's Gross Domestic Product (GDP) by sector. It is the second most important industry in terms of share of GDP, following the service industry [2]. In addition, the manufacturing industry supports Japanese industry with high productivity, as its nominal labour productivity per worker has been higher than the average for all industries in all years from 2011 to 2021. Thus, manufacturing enterprises, which are a major industry in Japan, are classified into three categories according to their scale: major enterprises, medium-sized enterprises and small enterprises. According to the Small and Medium-sized Enterprise Basic Act, Small and Medium-sized Enterprises (SMEs) are those with a capital of 300 million yen or less or with 300 or fewer employees, of which those with 20 or fewer employees are considered small businesses. In terms of the composition of the number of these enterprises, major enterprises account for only 0.3% of the total, while medium-sized enterprises account for 14.8% and small enterprises for 84.9%, making SMEs account for 99.7% of the total number of enterprises [3]. Furthermore, SMEs account for 68.8% of the total number of employees and 52.9% of the total value added. From these facts, it can be said that SMEs play an important role in the Japanese manufacturing industry. The deterioration of equipment is a problem for SMEs, which support Japan's manufacturing industry. A survey was conducted on the age of equipment by company size, with the index of equipment age as of FY1990 set at 100. According to this, as of 2017, the index for major enterprises was 148.0, while the index for SMEs was 191.8, a significant difference, indicating that the deterioration of equipment in SMEs is more serious than in major enterprises [4]. In addition, 36.5% of SMEs cited equipment failure as a risk that would make it difficult to continue operations. This indicates that the issue is how to maintain and continue to use equipment [5]. Furthermore, we compare capital investment by size in 2022 separately for tangible fixed assets and intangible fixed assets. With regard to tangible fixed assets, 94.6% of major enterprises and 76.6% of SMEs have invested in tangible fixed assets. Many SMEs invest in property, plant and equipment, although the proportion is smaller in SMEs [2]. Regarding the purpose of investment in tangible fixed assets, the highest proportion of investment in 2022 is for the renewal and reinforcement of obsolete equipment, at 64.3% of the total. Here, it is also possible to read the situation where the response to the deterioration of equipment is becoming more important [2]. In contrast, for intangible fixed assets in terms of capital investment by size in 2022, the figure for major enterprises is 83.1%, compared to 42.6% for SMEs. SMEs are not investing in intangible fixed assets, creating a large gap between major enterprises and SMEs [2].