Recently, the economic lot scheduling problem (ELSP) with common cycle time and shelf life restrictions has attracted the attention of several researchers. In this paper, a comparative study of solutions given by Xu and Sarker (2003) [Computers & Operations Research 30 (6), 925-938] with the results given by Viswanathan and Goyal (2000) [International Journal of Production Research, 38 (4), 829-836] are presented. Additionally, the paper makes some observations about two mathematical expressions, which contain a technical shortcoming.