This paper proposes a hierarchical approach to the machine loading problem when the workload and tool magazine capacity of each machine are restrained. This heuristic approach reduces the maximum workload of the machines by partially grouping them. This research deals with situations where different groups of machines performing the same operation require different processing times. This work proposes a solution that is comprised of two phases. In first phase, demand is divided into batches and then operations are allocated. In Phase II, the processing time of the operation is different for each machine group, which is composed of the same identical machines; however, these machines can perform different sets of operations if tooled differently. In partial grouping, each machine is tooled differently, but they can assist one another in processing each individual operation.

The assembly line balancing problem has been focused by many research works because the efficient management of the assembly line might influence not only the quality of the products but also the working conditions for the workers. This paper deals with U