Bas, E.Guner, L.B.2025-01-102025-01-1020250941-06431433-3058https://doi.org/10.1007/s00521-024-10738-6https://hdl.handle.net/20.500.13091/9781In this study, Crayfish Optimization Algorithm (COA) was examined. COA, which simulates crayfish’s summer resort behavior, competition behavior, and foraging behavior. COA is a successful heuristic algorithm originally proposed for continuous optimization problems. In this study, the continuous search space of COA was converted into a binary search space with eight different S- and V-shaped transfer functions. Thus, the Binary COA (BinCOA) algorithm was proposed to the literature. The success of BinCOA variations was analyzed on 25 different knapsack problems of different sizes. The most successful transfer function was determined as BinCOAV1. Since the success of BinCOAV1 fell behind many binary heuristic algorithms in the literature, BinCOA was developed with two different methods (bitwise operator and repair method). Thus, the Improved BinCOA (IBinCOA_RX) algorithm was proposed in this study. BinCOA’s local search ability and discovery ability in the binary search space have been improved. The resulting improved BinCOA variations (IBinCOAX (BinCOA with bitwise operator), IBinCOAR (BinCOA with repair method), and IBinCOA_RX (BinCOA with bitwise operator and repair method)) were analyzed in detail and the effect of each method added to BinCOA was detailed in the paper. The success of IBinCOA_RX has been proven by comparing it with eight different binary heuristic algorithms selected from the literature. According to the results, the IBinCOA_RX algorithm showed preferable success for binary optimization problems. In addition, in this study, the effectiveness of BinCOAV1 and IBinCOAX algorithms is also shown on a different binary problem, namely the uncapacitated facility layout problem (UFLP). © The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature 2024.eninfo:eu-repo/semantics/closedAccessBinary OptimizationCrayfishKnapsack ProblemS-ShapedV-Shaped Transfer FunctionsArticle10.1007/s00521-024-10738-62-s2.0-85213405232