Like many packaging operations, a variety of supporting equipment and a wide range of operational variables can affect overall machine performance. Normal operating speed, reliability, mean time between failures and changeover time all must be factored into the planning process. To accurately calculate these variables, MTS needed a simulation tool that would provide a detailed analysis of machine behavior with the ability to predict performance based on key metrics, such as costs, throughput, cycle times and utilizations. To minimize risk and eliminate much of the guesswork, MTS contracted with a consultant to prepare a simulation of the machine using Rockwell Software@ Arena@ simulation software. Using the Arena software allowed MTS to create an initial design concept that could identify potential problems in the machine packaging process and calculate the impact of the many variables that could occur.
Because of the sheer size and complexity of the machine and its high-volume production requirements, it was critical that the machine’s multiple components were optimally coordinated and synchronized to work seamlessly together. If one feeder station or labeler creates a bottleneck, the production rate of the entire system is limited. This is where the Arena software played a crucial role by helping to demonstrate, predict and measure system performance - specifically the effectiveness and efficiencies of design changes. In this case, the Arena software allowed MTS to test a multitude of process variables and application scenarios in a controlled environment under a variety of conditions. By manipulating the data inputs, engineers could then analyze propose changes, and refine operational efficiencies before beginning actual construction.
Simulating the machine’s operation with the Arena software helped bring a clear focus to the system components and their interdependencies,” Arnold said. “Even with the complexities of a system such as this, simulation can show it very accurately and provide a valid predication of overall performance."
The software’s systems-level analysis provided MTS with a valid picture of overall performance. Engineers were able to create a fundamental flow diagram of the packaging process. From there, they could define and validate the processing rates and reliability of the equipment, conveyor and feeder capacities, sensor locations, maintenance schedules and operator-staffing requirements.
“If you know that a feeder system has a 0.1 percent failure rate, you can build that into the Arena simulation to ensure the most realistic view,” Arnold said. “That’s why it was important that we use a simulation tool good at handling errors and exceptions. Without it, there can be a disconnect between what was initially simulated and what ends up really happening in real time.”
Another important feature of the Arena software is its ability to provide a working model or visualization of the machine in operation. This allows designers to see the location of bottlenecks, the impact of a machine stoppage or the effect of a particular control strategy. Then, by altering one or more data values, the same observations can be made on a “different” system. With visualization, engineers are able to verify that the model is an accurate representation of the physical system. It also will allow the customer to actually see the machine perform in a virtual world, giving them the confidence that it will meet their production and output requirements.
“Once the model is fully optimized, we can then begin the manufacturing process,” Arnold said. “With more detailed simulation we have more empirical data from machine operation and can go back to the Arena software and make sure it will perform based on the model. We can then design and build the robots and feeders based on the simulation data provided.” By using the Arena simulation software, MTS was able to cut its design time in half, from about two years to about 12 months. Moreover, MTS estimates the simulation will help reduce machine startup and installation time by about 60 to 70 percent.
Once the new packaging machine is up and running, engineers can continue to use simulation to further refine and improve operational efficiency. The end user benefits from a packaging machine designed to meet its specific performance requirements, with the flexibility to scale the system to meet future growth demands. As a result, MTS gains another satisfied customer, strengthens and expands its production capabilities, and adds another chapter to its long track record of business success.