This paper provides a comprehensive review of scheduling problems with setup times or costs, building upon the foundational work of Allahverdi et al. (1999). It covers over 300 papers published between 1999 and 2006, addressing various aspects of scheduling problems with setup times and costs. The review is organized into sections that discuss single-machine, parallel machines, flow shops, job shops, and open shops, among others. Key topics include batch and non-batch setup times, sequence-independent and sequence-dependent setup times, and different shop environments. The paper also highlights the development of algorithms and heuristics for solving these problems, including dynamic programming, genetic algorithms, and tabu search. Additionally, it discusses the computational complexity of different scheduling problems and provides a classification system for the setup time/cost literature. The review aims to provide a detailed overview of the advancements and challenges in the field of scheduling problems with setup times or costs.This paper provides a comprehensive review of scheduling problems with setup times or costs, building upon the foundational work of Allahverdi et al. (1999). It covers over 300 papers published between 1999 and 2006, addressing various aspects of scheduling problems with setup times and costs. The review is organized into sections that discuss single-machine, parallel machines, flow shops, job shops, and open shops, among others. Key topics include batch and non-batch setup times, sequence-independent and sequence-dependent setup times, and different shop environments. The paper also highlights the development of algorithms and heuristics for solving these problems, including dynamic programming, genetic algorithms, and tabu search. Additionally, it discusses the computational complexity of different scheduling problems and provides a classification system for the setup time/cost literature. The review aims to provide a detailed overview of the advancements and challenges in the field of scheduling problems with setup times or costs.