Mastering production time spread, efficiency increase and sequence compliance simultaneously are key design features of an assembly system for customer-specific products in large series production. Their implementation makes an important contribution in the strategy of a premium automotive company. This contribution analyses an assemply system with manual shop floor work places in comparison to a classical non-resting production flow system. The derived sensitivity graphs enable a critical discussion of the possible structural arrangements of the assembly system with high quality of the design features formulated at the beginning.