The Indices of Industrial Production published by the Ministry of Economy, Trade and Industry at the end of every month allow us to see production trends in Japan. Production, shipments, inventory and inventory ratio of industrial production are the leading indices, and the 2020 standard (index of 2020 = 100) is currently used. Looking at the long-term trend, it can be seen that the standard of production index is reduced every time there is a “shock”.

"When Will Japan’s Industrial Production Fully Recover?," Japan Spotlight

https://www.jef.or.jp/journal/pdf/257th_Economic_Indicators.pdf

Profile of Research Director Nobuo Iizuka

https://www.tokyofoundation.org/experts/detail.php?id=381