Homogeneous cycle times increase the performance of precast concrete plants

The uniform flow of pallets through the system is a core requirement for efficient production in automated precast concrete plants. This is called cycle time homogenization and requires a similar processing time of pallets at each individual station. A bottleneck with undesired delays occurs if one production pallet takes longer than the following one. The new Unitechnik master computer UniCAM.10 contributes significantly to cycle time homogenization. The software uses the configuration algorithm to optimize the layout of the elements on the production pallets in order to homogenize the processing times at the individual stations. The available work time is displayed so that the cycle time is also visible for employees. As a result, UniCAM.10 significantly improves the performance of precast concrete plants.

Two factors affect the productivity of a precast concrete plant with a pallet circulation system: the first criterion is pallet configuration, i.e. the layout of the precast concrete components on the production pallets. The optimum utilization of space is the ultimate goal, because the theoretical production capacity of the plant is higher the more square meters can be placed on one pallet. UniCAM.10 features a special algorithm to optimize pallet configuration. It allows, for example, the nested layout of elements, so that only minimal space is unused. The software simultaneously ensures that minimum clearances are kept between the elements and that built-in parts and product types are also taken into consideration.

Short, homogeneous cycle times are the second criterion for the productivity of a system. This means the uniform, swift flow of pallets through the circulation system. This requires that every single pallet takes approximately the same amount of time at any station. The processing time of a pallet is, for example, determined by the number and type of built-in parts and can be regulated through configuration. The configuration algorithm of UniCAM.10 skillfully mixes multiple orders to homogenize the processing times of pallets as much as possible, and thus contributes vitally to cycle time homogenization.

Signal lights prevent bottlenecks
Consecutive stations must have comparable processing times to ensure a smooth production process in sequential production. Wait times occur in front of slower stations if processing times differ from each other, and waiting pallets may block upstream work stations. The processing time at the stations is the result of the number and complexity of elements, which is determined by pallet configuration. It is also affected by the necessary production steps, which are a result of the functional layout of the system. The employees at the work stations see the remaining processing time for the current pallet on large displays. A signal light function also shows if processing is highly elaborate and therefore hard to manage with existing staff. In this case it is recommended that a standby employee is added to maintain the cycle time. For systems with very different products, a system layout with parallel production lines is also very sensible, so that pallets with a shorter processing time can pass other carriers. These complex material flows are also coordinated by the master computer.  In this case, flow charts ensure the optimum distribution of pallets on the production lines.

Self-learning system
When calculating the processing times at the individual stations, the pallet configuration algorithm first uses forecasts. It then receives feedback on the actual time required. The master computer uses this information to successively improve its forecasts and thus achieves even better results for pallet configuration and cycle time homogenization.