The company serves more than 9,000 institutional pharmacies in the long-term care and correctional-facility markets worldwide with a wide range of automated and semi-automated packaging machines and hundreds types of consumable products.
The company’s existing robot-automated packaging machines are designed to fill, seal and label punch cards at speeds of up to 12 cards per minute. A large overseas pharmacy contacted MTS about developing a medication packaging system that would produce a single punch card supplying a patient with a weekly or monthly amount of medication on a single card, with each individual compartment providing a daily dose of various medications. For example, if a patient needed to take a medication at four different times during the day, the machine would produce a 4x7 punch card to furnish a one-week supply.
Because of the need to package multiple medications into multiple punch card compartments, the size of the machine would be considerably larger than any of the company’s previous designs. Instead of employing a single robot, this machine could potentially require up to a dozen or more robots working together simultaneously. Instead of a single conveyor and feeder station, like many of its other machines, this one would employ multiple feeders to accommodate the multiple medication requirements.
With such complexities, MTS needed to test and validate a multitude of variables upfront in order to minimize risk, optimize engineering time and gain full buy-in from the customer. MTS also needed to provide its customer with an accurate cost estimate to build the machine, determine the required footprint, and verify the production rate and throughput. According to Richard Arnold, senior vice president of software development and information technology (IT) for MTS “The only way we would be able to verify the performance of the machine and calculate the many variables that can occur in the process was through simulation.”
MTS contracted with a consultant to prepare a simulation of the machine using Rockwell Software Arena simulation software from Rockwell Automation. 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. With visualization, engineers are able to verify that the model is an accurate representation of the physical system. It also will allow users 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, MTS can begin the manufacturing process.
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.
