The revised mathematics of life cycle sustainability assessment

In a recent paper, Sadhukhan et al. (2021) describe “the mathematics of life cycle sustainability assessment”. This is an ambitious task for a 12-page paper, given that a previous text on the mathematics of life cycle assessment (Heijungs and Suh, 2002) took 250 pages, for a smaller subject, and that another paper (Heijungs et al., 2013) which was more modest in announcing an approach “toward” the mathematics of life cycle sustainability assessment was already 12 pages. Of course, a paper from 2021 can build on and refer to such previous works, and thereby be more concise. The curious fact is, however, that Sadhukhan et al. (2021) do not refer to and neither build on those previous publications. They even ignore other related works that were published in the Journal of Cleaner Production, including Gwak et al. (2003), Suh and Huppes (2005), Heijungs and Suh (2006) and Islam et al. (2016).