In this study, real life assembly line balancing problem of a dishwasher producer is addressed. The line considered is a multi-model assembly line and real life problem instance consists of approximately 300 tasks, 400 precedence relations and 70 stations per product model. The number of stations used to meet a specified production rate is desired to be minimized. To do this, a type-one simple assembly line balancing problem instance is considered for each product model. Due to thelarge size of the problem we could not find the optimal solution of the problem by mathematical programming methods. In order to find good solutions in short times an adaptive simulated annealing algorithm is developed. Performance of the algorithm is tested on several problem instances from the literature and found to be satisfactory. Then it is used to solve the real life problem instanceconsidered and a better solution than the current one is obtained.