I celebrated my 71st birthday in February 2021, amid the raging COVID-19 pandemic. Last August, due to the impact of COVID-19, I decided to take a break from my consulting work, which I had been doing for over a decade, and began developing Tera calculation software. At the same time, I decided to create this website. My motivation for creating this was that, at Professor XX's invitation, I participated in monthly study sessions for four to five years as a junior co-author of "Logistics XX." Looking back on these sessions, I was always a listener, except for my area of ​​expertise. I resolved to at least thoroughly examine my area of ​​expertise and bring it to a level appropriate for this book. Professor XX encouraged me, saying, "The number of lines in a book is limited. Trim what you want to say and focus on the core, and leave the rest for another time." This book was published by the XX Research Institute in April of last year. In this work, I wrote about "A method for estimating distribution center size from shipping data," but I felt that there were some areas that I lacked explanation, and I felt the need to fill in the gaps. I worked for a logistics equipment manufacturer for 10 years, then for a logistics operations company for 10 years, and then returned to the manufacturer for another 10 years. After that, I worked as a self-employed consultant for over 10 years, all of which were related to distribution centers. During that time, I worked as a logistics consultant under the late Professor Mutsumi Nakanishi at the logistics operations company. Later, I learned EIQ analysis, a logistics analysis method, from the late Professor Shin Suzuki. Upon going independent, I took over Professor Suzuki's consulting company, the Logistics Technology Research Institute. Professor Suzuki, who had a strong desire to popularize EIQ analysis, passed away last June, and I felt compelled to write about EIQ analysis as his successor. In writing this book, I struggled with how to explain the EIQ method. There were some ideas and calculation methods that did not align with Professor Suzuki's intentions. In the end, I decided to leave the formal EIQ method to others and instead compile the calculation methods I have used in practice. While some of the programs incorporate EIQ techniques, I also incorporate traditional calculation methods without adhering to the EIQ method. I have compiled these self-developed calculation programs into the "Tera Calculation" software. In 2021, we considered the software configuration, and in April 2022, we created a prototype of Tera Calculation 0 (data processing), Tera Calculation 1 (analysis and aggregation), and Tera Calculation 2 (distribution center size calculation). Since 2022, two universities have been using "Tera Calculation (prototype)". In 2023, we created Tera Calculation 3 (utility software for calculating the installation area of ​​logistics equipment and creating programs related to logistics systems) . In August 2025, we began work on creating a website.