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Dr Constantine Goulimis

Delivering industrial-strength software using mathematical optimisation: Lessons from 40 years of doing the same thing.

Greycon started in 1985 as a spin-off from Imperial College’s Industrial Systems Group, where I was Deputy Director. The initial focus was on an exact (not heuristic) solutions to the cutting stock problem, as applied to the paper industry. This problem has many facets and a commercially viable implementation actually contains more than a dozen algorithms; the latest release incorporates elements of machine learning. Over the next 33 years, the company grew. X-Trim, the solution to the cutting stock problem, has become the world market leader in its sector with clients in more than 40 countries.

At the time of writing, more than 85% of North American paper production and more than 30% of China’s goes through X-Trim. I have been the X-Trim Product Manager since the beginning in 1985 (as well as CEO for the last 16 years). In addition to X-Trim, Greycon also develops, sells and supports two other products: opt-Studio is a scheduling system (with some mathematical optimisation content) and GreyconMill, an industry-specific manufacturing execution system.

In 2018 Greycon won the prestigious Queen’s Award for Enterprise. Overall around 500 plants around the world use Greycon software for their daily operational needs. These plants encompass a broad spectrum beyond the original paper industry, e.g. include Honda in the US (steel coil slitting for all US car production) and De La Rue (UK banknote production). At the beginning of 2018, I decided that I would seek an exit for Greycon. In October 2018, Greycon (where I was a 52% shareholder) was sold to Jonas, a division of Constellation Software, a US$15+ billion company listed on the Toronto stock exchange.