Discussion on a new extension of the FGM copula with application in reliability

TL;DR

This paper reviews and corrects the admissible parameter range and typographical errors in a recently proposed extension of the FGM copula, emphasizing its application in reliability analysis.

Contribution

It provides corrected parameter ranges and addresses errors in a recent study on an extended FGM copula, enhancing its reliability for practical use.

Findings

Corrected the admissible range of the copula parameter a

Identified and fixed typographical errors in the original paper

Clarified the applicability of the extended FGM copula in reliability

Abstract

A new extended Farlie-Gumbel-Morgenstern copula recently studied by Ebaid et al. [Comm. Statist. Theory Methods, (2020)] is reviewed. The reported admissible range for the copula parameter a is incorrect and some typos are also found in their paper. Corrections to the admissible range of the copula parameter a and typos are presented here.