The complex (bio)chemical reaction systems, frequently possess fast/slow phenomena, represent both difficulties and challenges for numerical simulation. We develop and test an enhancement of the classical QSSA (quasi-steady-state approximation) model reduction method applied to a system of chemical reactions. The novel model reduction method, the so-called delayed quasi-steady-state approximation method, proposed by Vejchodský (2014) and further developed by Papáček (2021) and Matonoha (2022), is...