Real systems are neither black nor white; they are “grey,” that is, imperfectly known.

Grey system theory has been widely acknowledged as a solid methodology to approach problems under uncertainty and lack of information. Since the theory’s inception by Chinese scholar Deng Julong in 1982, multiple academic papers have been published with applications in many industries and subject areas. The author provides a historical review and bibliometric analysis of the peer-reviewed publications on grey system theory for the period from 1996 to 2011. A total of 596 publications were retrieved from ISI Web of Knowledge and identified for analysis. The scope of the search was limited to two areas of grey system theory: grey relational analysis (GRA) (453 papers) and grey prediction (GP) (143 papers). The dominant language of publications (99%) was English. The number of publications by year increased, with 2011 showing about 120 papers on GRA and 20 on GP. The majority of the papers were produced by authors in China and Taiwan (78% of GRA and 88% of GP papers). Engineering was by far the most common subject area for publications (45% for GRA and 54% for GP), followed by mathematics and computer science. GRA papers were published in 194 journals and GP papers appeared in 89 journals. The most productive journals by title were Journal of Grey System, International Journal of Advanced Manufacturing Technology, and Expert Systems with Applications. The most cited article was published in the International Journal of Machine Tools and Manufacture and had 88 citations.

The intended audience of the paper includes academics and practitioners interested in grey system theory.

The review is limited by the source database (ISI Web Knowledge) and the selected subareas of grey system theory. For example, in Google Scholar, the most cited paper, mentioned above, has 241 citations (as of January 2015).

Readers who are interested in in this topic can find additional information on the subject in other sources [1,2].