This paper presents a simulated annealing approach to solving dual-criteria single-model and deterministic (SMD) assembly line balancing (ALB) problems. The first objective is to minimize the idle time of an assembly line, i.e., to minimize the number of workstations for a given cycle time, while the second objective is to minimize the workload deviation among workstations. To find such solutions, this study proposes an iterative method using a simulated annealing. This method sequentially minimizes each energy function associated with the idle rime and the workload deviation. When no further change in energy occurs, a line balancing solution is finally found. To show the effectiveness of the proposed method, case studies are carried out for solving a set of problems in literature, and the results are compared with those of the literature. The comparison result shows that the proposed method can generate better solution quality especially for large size problems.