In make-to-stock processes and portions of assemble-to-order processes where products are manufactured on a repetitive basis, the production process should be synchronized such that every upstream operation produces at the rate required to satisfy demand. In a pull system, synchronization is achieved by setting the cycle times (CT) at every upstream operation according to the CT at final assembly. The individual task times used for traditional line balancing are determined for whatever particular product is being produced. In mixed-model production, balancing is based upon the weighted average task times for the product models in the mixed-model sequence. In synchronous production, every operation produces just enough to satisfy downstream demand. The product mixes and volumes keep changing, and as a consequence, bottlenecks appear at places other than at final assembly. The rope in drum–buffer–rope can be a kanban card issued from the bottleneck operation to the first stage of the process.