Material flow optimization using plant simulation
Use Case for performing a material flow optimization in Plant Simulation
Target and result definition of material flow optimization
At the beginning of a material flow optimization, the goals to be achieved and the desired results should always be defined. Consequently, the selection of the software program for the creation of the material flow simulation is also made. In principle, many different tools such as visTABLE are suitable. For the use case, the Plant Simulation program from Siemens was selected, since it has the possibility to realize a digital twin according to the current state of the art and provides a wide range of analysis tools. Furthermore, the software’s own SimTalk language enables the programming of methods that allow the digital model to be built up in a customer-specific and detailed manner.
Optimization of lead time in Plant Simulation
On the basis of a throughput time optimization for a production station, we will show you how to carry out a material flow optimization with Plant Simulation. Within the production, a total of five different products are manufactured on four machines. An analysis or assessment of the current situation should identify the bottleneck that is responsible for high throughput times. A subsequent optimization is to eliminate this. As in the classic material flow analysis, an ACTUAL model of the current material flow must first be created. On the basis of this, the subsequent optimization can be carried out. When using a digital model as a tool, this represents the model of the ACTUAL state.
What are the components of material flow optimization in Plant Simulation?
Based on the goals and data, the material flow optimization can be realized in Plant Simulation. The model for manufacturing contains the following components:
- Twin configuration tables
- Sankey diagrams
- Histogram for displaying the throughput times
- Sub-networks for the representation of transport routes
- Machines
- Subnetworks for experiments and methods
- Visual display for the number of processed products
Evaluation & presentation of the data
The digital model is used for material flow optimization, evaluation and presentation of the data. For this purpose, Plant Simulation offers different tools. These can be dynamic or static. For analysis, a histogram is implemented, which dynamically records and displays the throughput times of the individual products. The flow is shown visually by means of a Sankey diagram. The figure shows only the flow of the product “PartA” as an example.
Assessment & Vulnerability Analysis
Based on previously defined key figures and assessment criteria, a weak point analysis is carried out to locate the bottlenecks. When looking at the histogram and the Sankey diagrams, it becomes apparent that “PartA” clearly exceeds the limit for the maximum throughput time. According to the analysis, the reason for this is the insufficient delivery times of the raw parts and too few parallel stations, which results in waiting times during processing. A total of three products are manufactured in machine 1. This shows the potential of material flow optimization.
Optimization of the material flow in Plant Simulation
The finished ACTUAL model is then used to optimize the material flow and thus create a TARGET model, which can then be implemented. Here, not only the findings from the weak point analysis, but also your customer requirements are taken into account. This material flow optimization in Plant Simulation can be divided into rough and detailed planning.
By means of experiments iteratively to the optimal material flow
Based on the previously defined goals of material flow optimization, an attempt is made to develop an ideal concept, which can be finalized in the subsequent detailed planning. It should be noted here that restrictions of all kinds are not initially taken into account. Here, simulation offers the possibility to efficiently implement the necessary changes and thus to create as many concepts as possible in a short time. For mechanical production, no parallel stations are considered due to lack of space and only attempts are made to optimize delivery times. Plant Simulation offers the possibility to configure experiments to find out the optimal delivery time. The figure shows the result of the experiments, whereby a maximum delivery time between 7:30 min and 8:00 min emerges.
Result of material flow optimization in Plant Simulation
Within detailed planning, the results from rough planning are used to work on a real solution that takes all restrictions into account. After the material flow optimization in Plant Simulation, all precautions are taken to enable realization. For mechanical production, all delivery schedules are adjusted in such a way that the raw parts only arrive at the production line at a maximum of every 8:00 min.
