Comments on “Comparative analysis of standby systems with unreliable server and switching failure” [Relib Eng Syst Saf 2016; 145: 74-82]

This work first illustrates that Figure 9 which is given by Kuo and Ke (2016) is incorrect. The incorrect of Figure 9 is due to the inaccuracy of Equation (18). We point out some other deficiencies and errors found in the above referenced paper, which imply that the numerical results are not trustworthy. We suggest the modified expresstions of the steady-state availabilities for three different configurations. Some numerical examples are presented to illustrate that the new expressions of the availabilities is correct.