In the era of big data, the grey system theory based on poor information data mining has sprung up. It has become an effective tool for people to extract valuable information from massive data. A large number of scholars have devoted themselves to the research of grey system theory and made important contributions to the innovation, development and in-depth application of grey system theory in many scientific fields.

In the past 40 years, grey system method and model have been widely used in many fields, such as social science, natural science and engineering technology, which has led to innovation and progress in various fields. More and more people interested in grey system theory and a lot of new results have been obtained in recent years. In particular, successful applications in many fields have won the attention of the international world of learning.

Scholars from more than 100 countries and regions in the world have published more than 300000 documents of grey system research and applications.

Over the years, our research has been highly commended by many first class scholars, such as Julong Deng, the founder of grey system theory, L. A. Zadeh, the founder of fuzzy mathematics, Hermann Haken, the founder of synergetics, Robert Vallee, former president of the World Organization of Cybernetics and Systems, James Tien, former vice-president of IEEE and member of the American Academy of Engineering, K.W. Hipel, former president of The Academy of Science of the Royal Society of Canada and , Jifa Gu, former president of the International Federation for Systems Research. And praised or cited positively by more than 100 academicians from academies of science and engineering all over the world.

On the 7th of September, 2019, Angela Dorothea Merkel, then German Chancellor, praised grey system theory in her speech at Huazhong University of Science and Technology. She said that the work of Professor Deng Julong, the founder of grey system theory and Professor Liu Sifeng, a developer of grey system theory, “have made a profound impact on the world.”

Indeed, such positive feedback on our work has given us a strong impetus to devote ourselves to the research of grey system theory.

In order to commemorate the 40th anniversary of the establishment of grey system theory, this memorabilia is specially compiled and shared with all readers.

In 1982, professor Julong Deng has published the first paper on Grey System Theory in System and Control Letters.

In 1984, the first national academic conference on grey system theory and applications which chaired by professor Julong Deng was held in Taiyuan.

In 1985, Wuhan grey system consulting department was established.

In 1985, professor Julong Deng has published the first book on Grey System Theory by National Defense Industry Press (In Chinese).

In 1986, the course of grey system theory is included in the postgraduate training plan at both of Huazhong University of Science and Technology and Henan Agricultural  University.

In 1987, Wuhan (National) Grey System Research Association which professor Julong Deng served as the president was established.

In 1989, the first Journal of “The Journal of Grey System” which edited by professor Julong Deng was released by “Research Information Ltd” in the UK.

In 1990, a research direction for training doctoral students in the field of grey system theory has set up at system engineering discipline of Huazhong University of Science and Technology.

In 1991, the grey system research office which professor Julong Deng served as the director was established in the Automation Department of Huazhong University of Science and Technology.

In 1996, The 9th national grey system academic conference attended by scholars from both sides of the Taiwan Strait was held in Wuhan.

In 1997, Professor Julong Deng ranks first in the number of cited documents according to the first citation report released by China Science Citation Database (CSCD).  

In 1997, Regional Grey System Society of Taiwan was established.

In 2000, with the approval of the Academic Degrees Committee of the State Council, Nanjing University of Aeronautics and Astronautics has established a doctoral degree authorization point for management science and Engineering which Grey System Theory is listed as the first leading research direction.

In 2000, Institute for Grey Systems Studies was established at Nanjing University of Aeronautics and Astronautics.

In 2002, the first Doctor's Forum on Grey System Theory was held in Nanjing.

In 2004, both the number of publications on grey system theory and the number of citations of IGSS at NUAA are ranked No.1 in web of science.

In 2005, the Grey System Society of China, CSOOPEM, was approved by the Chinese Association for Science and Technology and Ministry of Civil Affairs, China

In 2006, for the first time, the national grey system academic conference was supported by China Higher Science and Technology Center which professor Tsung-Dao Lee served as the director.

In 2007, the first IEEE International Conference on Grey Systems and Intelligent Services was held in Nanjing.

In 2007, professor Julong Deng won the award of founder of Grey System Theory at the 2007 IEEE International Conference on Grey Systems and Intelligent Services.

In 2007, the Technical Committee of IEEE SMC on Grey Systems was established.

In 2008, the course of grey system theory of Nanjing University of Aeronautics and Astronautics was rated as a National Excellence Course.

In 2009, Xuesen Qian, the first winner of the National Highest Science and Technology Award of China, sent professor Sifeng Liu and Dejin Song a letter to encourage their research work.

In 2010, the teaching team of grey system theory which lead by professor Sifeng Liu was rated as a National Excellence Teaching Team of China.

In 2010, the Journal of “Grey Systems-Theory and Application” which edited by professor Sifeng Liu was launched by Emerald Group in the UK.

In 2011, professor Julong Deng was elected as the honor fellow of the World Organisation of Systems and Cybernetics at the joint conference of the 15th WOSC International Congress on Cybernetics and Systems and 2011 IEEE International Conference on Grey Systems and Intelligent Services.

In 2012, the course of grey system theory of Nanjing University of Aeronautics and Astronautics was selected as a National Excellence Sharing Course of China.

In 2012, the first Workshop of European grey system research collaboration network chaired by professor Yingjie Yang was held at De Montfort University.

In 2013, professor Julong Deng, the founder of Grey System Theory, passed away.

In 2013, the 2013 IEEE International Conference on Grey Systems and Intelligent Services was held in Macau.

In 2013, Professor Sifeng Liu was selected for a Marie Curie International Incoming Fellowship (FP7- PEOPLE- IIF-GA-2013-629051) of the European Union.

In 2014, an international network project entitled “Grey Systems and Its Applications” (IN-2014-020) directed by professor Yingjie Yang was funded by The Leverhulme Trust.

In 2014, a book Series of Grey Systems in Chinese which edited by professor Sifeng Liu were launched by Science Press.

In 2015, the International Association of Grey System and Uncertain Analysis (GSUA) was established.

In 2015, the first International Congress of GSUA was held in Leicester, UK

In 2017, Polish Scientific Association of Grey Systems which Dr. Rafał Mierzwiak served as the founding president was set up.

In 2017, the 2017 IEEE International Conference on Grey Systems and Intelligent Services was held in Stockholm, Sweden.

In 2017, the book Grey System Theory and Its Applications, which authored by Prof. Sifeng Liu and published by Science Press, is identified as the No.1 top sited books in the pandect of natural science of China.

In 2017, Professor Sifeng Liu has been selected to be one of the top 10 shortlisted promising scientists in the MSCA 2017 Prizes.

In 2018, the course of grey system theory of Nanjing University of Aeronautics and Astronautics was selected as a National Excellence Online Open Course

In 2018, Grey Systems Society of Pakistan was established.

In 2019, Turkish Association of Grey Systems Theory which professor Erdal Aydemir served as the founding president was established.

In 2019, the 2019 International Congress of GSUA was held in Bangkok, Thailand.

In 2019, Angela Dorothea Merkel, then German Chancellor, praised professor Julong Deng, the founder of grey system theory, and professor Sifeng Liu, a developer of grey system theory.

In 2020, the 2020 International Congress of GSUA was held in Nanjing.

In 2020, professor Sifeng Liu enters Stanford’s list of top 2% scientists in the world.

In 2020, professor Sifeng Liu ranked first in the list of highly cited authors in the field of Systems Science, at the same time, other 4 grey system scholars professor Yaoguo Dang, professor Naiming Xie, professor Zhengxin Wang and professor Dang Luo enter the list of top 100 highly cited authors in the field of Systems Science.

In 2020, the course of grey system theory of Nanjing University of Aeronautics and Astronautics was selected as a National first class offline course.

In 2020, the course of grey system theory of Nanjing University of Aeronautics and Astronautics was selected as a National first class online course.

In 2021, a book Series of Grey Systems which edited by professor Sifeng Liu were launched by Springer-Nature Group

                                                                                                                                          Sifeng Liu 

Institute for Grey Systems Studies Nanjing University of Aeronautics and Astronautics