This article considers the stress-strength modeling for calculating of the stress-strength reliability of a coherent system as a function of the stress-strength reliabilities of its components. The system components may experience the same or different stress levels. We have found some mistakes in examples given by Bhattacharya and Roychowdhury (2013) due to misapplication of the system reliability when the system components were subjected to a common stress level. We show that the stress-strength reliability of a system with different stress levels does not include the case when the system components are subjected to a common stress level as a special case and give a correct argument. Their result for the case of different stress levels is correct.

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