“…Singularly perturbed delay differential equations are in to the picture in different fields of science and engineering, for instance, control theory (Van Harten and Schumacher 1978), chemical processes (Adomian and Rach 1983), Problems with water quality in river networks (Samarskii and Vabishchevich 1995;Tikhonov and Samarskii 1972), semiconductor drift-diffusion model (McCartin 1985), chemical kinetics (Epstein 1992), etc. In recent years, several computational techniques have been constructed for singularly perturbed time delayed parabolic partial differential equation (PDE), for instance, fitted mesh finite difference method (Ansari et al 2007;Selvi and Ramanujam 2017), fitted operator finite difference method (Bashier and Patidar 2011), high-order parameter-uniform scheme (Kumar and Kumar 2014), upwind finite difference scheme with adaptive mesh (Gowrisankar and Natesan 2014), fitted Numerov method (Rao and Chakravarthy 2014), an overlapping Schwarz domain decomposition (Singh et al 2018).…”