In high diversity, Just In Time production environments, mixed-model assembly lines aim at producing a large amount of end products that use alternative variants of components used in the assembly process. Therefore, the availability of parts required at the border of the assembly line is critical for the production process. To ensure the availability of parts needed on the line, three line feeding modes are commonly used in practice: line stocking, kitting and sequencing. The relative performance of each mode, in terms of average total operating cost, depends on various factors such as the diversity of components, parts’ physical features (i.e. weight and volume), to name a few. The impact of such parameters on the performance of line feeding modes remains still weakly studied in the literature. Through an empirical approach based on a real case, our study aims at evaluating the average total cost pertaining to each mode. The total cost includes parts preparation before assembly, picking, in-plant transportation and storage costs. A thorough comparative study enables then to characterise situations which make one mode less costly compared with the others. Each situation corresponds to specific values taken by parameters that are considered in the cost formulation.