One group of mathematical models for supercritical fluid extraction from plants is based on the Broken and-Intact Cell (BIC) concept. A simplified BIC model with analytical solution, derived for the extraction of vegetable oils from seeds, was published in 1994. It has been used by several researchers also for the extraction of other solutes from other plant parts. The aim of this contribution is to show how the simplified BIC model was derived from Lack's model, for what type of extractions it is suited and where it fails, and how the BIC models have been improved since then. (C) 2017 Elsevier B.V. All rights reserved.