Shown here is a fulfillment operation in action using mobile robotic automation. The mobile inventory system is set up for a range of small devices.

Amy Villeneuve

January 10, 2011

11 Min Read
Robots Doing It for Themselves

Medical devices must meet exacting standards of quality and excellence—not only in their manufacture, but also in their subsequent handling and delivery to consumers. Medical professionals and their patients require and demand prompt and accurate service, so devices must arrive undamaged and within expiration date parameters. The challenges inherent in medical materials handling can be daunting. Fortunately, there are a variety of automation options available for medical supplies and devices that can improve the quality of service and enhance customer satisfaction.


Medical devices, by nature, have unique and specialized needs for materials handling. Of utmost importance is product quality. Although product expiration is hardly a new concept in materials storage and delivery, it is critically important for medical materials. Similarly, tracking a product by lot in the event of a recall is a common practice in materials handling. But for medical devices, a recall is extremely time-sensitive and must be enacted everywhere along the distribution network as rapidly as possible. Some medical device producers even have specific requirements for certain countries and customers. Medical devices may also need to be segregated within the distribution center for quarantine or sterility. In addition, medical devices must meet the standards of various regulatory bodies, such as FDA. A single, high-quality fulfillment method can help by requiring less integration, thus minimizing the number of systems that require validation.

In all of these cases, accuracy and quality control are extremely important. A rapid response to a recall must ensure complete compliance to remove every item in the lot being recalled. Therefore, any materials handling method should strive to improve accuracy by using a single operational work flow from stocking to shipping, including scanning the product at every step and reducing the number of touches required to move the product through the distribution center.

The customers served by medical device manufacturers do not typically stock a large amount of inventory. When a device is needed for imminent surgery, for example, the device typically needs to be shipped the same day as it is ordered and arrive the following day. This short lead time emphasizes the usefulness of a highly responsive automation system, which can prioritize same-day shipping orders.

Important Criteria for Automated Materials Handling

This alternate view of the small device inventory setup provides a a glimpse of the pick station, from which the worker calls inventory over to fill specific orders.

Exacting standards for quality, accuracy, and quick order processing can be addressed through the use of automated material handling systems. Automation can improve storage, tracking, and handling of medical devices to support rapid response times and exceptional storage needs. It can also significantly reduce costs in terms of manpower, use of space, and productivity. When selecting an automation system, several criteria should be considered, some of which are unique to the medical device industry.

Flexibility. Any automation system should be highly flexible. Medical devices have a high degree of variability; they can be minutely small, such as hearing aids and microsensors, or large and bulky, such as powered wheelchairs or large pieces of instrumentation. They may be long and slender or squat and heavy. They may be stored individually, in cases, or in bulk on pallets. They may be in high demand or form part of seldom-ordered but still critically important devices.

The medical device industry is constantly changing. New patient needs give rise to new device designs, and devices are refined to better serve the needs of customers. As a result, the inventory profile of distribution centers must change frequently, sometimes radically. Any automated material handling system should be able to adapt to these changes. It should be able to scale easily to accommodate changes in throughput and demand due to growth, seasonal demand, and the acquisition and consolidation of businesses. A scalable system reduces risk and uses capital more efficiently. Ideally, a system can achieve the following:

  • Be phased in over time, as needs change.

  • Fit within an existing distribution center’s footprint.

  • Make use of vertical space.

  • Be easy to move physically if changes occur, such as expansion into additional space or an entirely new distribution center.

Handling. Medical devices may also have specialized handling requirements. They may be particularly delicate or come in unusual shapes and sizes, and in some cases, both conditions may apply. For example, some stents used for cardiac surgery must remain sterile and are packaged in 4- or 5-ft-long boxes. The devices are awkward—too long for conveyors and vulnerable to crush damage. As a result, many conventional material handling systems are unsuitable for stents and similarly unwieldy or fragile medical devices. Any automation system should be able to accommodate the unique dimensions and needs of a product.

Robustness and Efficiency. The automation system should be robust; that is, it should have no single point of failure. If the system is dependent on a single conveyor, and that conveyor breaks down, the entire distribution center grinds to a halt. Modular automation systems using a parallel processing approach are less vulnerable to mechanical failure and, in some cases, can even be self-healing, ensuring smooth and productive operation throughout the distribution center’s hours of operation.

This diagram illustrates the work flow of inventory through a distribution center using a robotic automation system.

In addition, the automation system should improve productivity and working conditions. Almost any automation system operates more quickly and efficiently than handpicking products and placing them into carts. But in light of the medical device industry’s particular sensitivity to human health, an automation system with ergonomically designed user interfaces also improves worker performance and satisfaction while aligning with the goals and philosophy of the company.

How Automated Systems Meet the Challenge

New automated material handling systems provide welcome alternatives to more conventional systems. Manual pick-to-cart systems are slow, labor-intensive, costly, and incur frequent quality control problems. Conveyor systems are monolithic and not suited to handling oddly shaped or fragile devices. The remaining alternatives include carousel systems, automated storage-and-retrieval systems (ASRS), and mobile robotic fulfillment systems.

Carousel systems provide storage tailored to the product, avoiding the problems that conveyor systems have  handling oddly shaped products. These large, rotating shelving units bring products to workers, reducing labor costs and improving accuracy. However, carousel systems have several drawbacks. Like conveyors, they are inflexible and vulnerable to single points of failure. They also create bottlenecks in throughput: if a product is stored elsewhere on the carousel, the worker must wait until the carousel rotates around to their location. A limited number of devices may be picked from the carousel at any one time, and products cannot be picked and replenished at the same time. In addition, not all products are suited to carousels, particularly large and bulky devices. Finally, carousel equipment can be a large capital expenditure that is difficult to scale as a business grows.

ASRS incorporate some of the aspects of a carousel system and may even incorporate horizontal or vertical carousels in their design. An ASRS environment maximizes use of vertical space and employs some degree of automated retrieval, whether manually directed or entirely automated. Some ASRS use a fixed-aisle storage-and-retrieval system in which products are stored vertically in narrow aisles and retrieved entirely under automated robotic control. Such systems use a machine that moves along a track running the length of the aisle and vertically up the frame of the rack, employing some variant of robotic arm to place and retrieve products.

A rendering shows a verticalized warehouse using mobile robotic automation. In this setup, mobile robots would move from level to level on an elevator to retrieve goods for the warehouse workers, who would be located on the ground floor for order picking.

Although this system makes good use of the cubic volume of a distribution center and can reduce labor costs and improve accuracy, it is still vulnerable to all of the same problems that carousels face: single points of failure, large capital expenditure, specific physical building requirements, and monolithic installations that do not scale well with growth and change in business parameters. Additionally, once built, these systems are part of the fabric of the physical building, which makes them all but impossible to relocate. This means the planning horizon for the use of an ASRS-equipped building is typically 10 years or more. ASRS is also not well suited for variability in size characteristics of the SKU (stockkeeping unit). As a result, multiple work flows often need to be developed to accommodate different product types, a potentially negative effect on quality.

Mobile robotic systems address these vulnerabilities. In a mobile robotic fulfillment system, individual, autonomous robots pick up modular storage pods and deliver them to workers for both replenishment and picking. Because the system uses dozens or even hundreds of robots, there is no single point of failure. If a single robot fails, its work is simply assigned to other robots. Inventory is distributed throughout the storage pods so that a high-demand product may be delivered to multiple workers at the same time.

Such robotic fulfillment systems are highly modular, flexible, and scalable. They require no monolithic structures other than mezzanines and lifts to maximize use of vertical space. As a business grows, more robots and storage pods can be added to the system so that capital expenditure occurs only when needed, greatly reducing financial risk and increasing capital efficiency. Transition to a mobile robotic system can be gradual, implemented first in a small section of the distribution center and then incrementally expanded to minimize disruption. And as a business outgrows its distribution center, the components of the system can be easily moved and redeployed in a new, larger facility.

Storage pods can be customized to the specifications and requirements of the products. Almost any product can be stored on specially designed storage pods. As product specifications change and as new products are developed, storage pods can be modified or new storage pods can be designed to meet those needs without changing the entire infrastructure. Entire pallets may be inducted into storage, reducing replenishment costs.

Mobile inventory systems can also be developed for larger devices.

Sophisticated computer software enables mobile robotic systems to optimize storage and resource usage. High-velocity products are stored closer to picking stations, while products in the long tail are stored farther away, improving picking speeds. (Long tail refers to a retailing strategy of selling a large number of unique items in relatively small quantities—usually in addition to selling fewer popular items in large quantities. This multiple-SKU, small-batch inventory is the long tail.) Products are dynamically tracked by expiration date, lot number, and serial number. They can be segregated for quarantine or placed on inventory hold at any time and at any step in the order process. In the event of recall, all affected product can easily be quarantined from the usable product. Work flows can be tailored to suit particular business needs and specific company quality processes and checks.

Using laser scanners and pick-to-light systems, mobile robotic systems vastly improve accuracy and quality. Because the product is scanned at each step of the fulfillment process, from the moment it is stored in the system to the point at which it is physically shipped to a customer, a high degree of accuracy can be ensured. The software also monitors and reports problems as they occur, such as damaged or misplaced products, so that quality can be maintained at a high level throughout the system. Additionally, the system can track the efficiency and performance of individual workers, assigning them work to better balance the workload throughout the distribution center and achieve a high level of throughput.

The work environment provided by a mobile robotic system is designed for ergonomic use, which also improves productivity as well as worker satisfaction. Among other benefits, mobile robotic systems tend to be unusually quiet, avoiding the stressful noise generated by large equipment such as conveyors, tilt trays, and carousels.


In this era of Six Sigma, inventory optimization, and lean processing, customers demand rapid delivery of medical devices and expect those products to arrive intact and ready for use. Automated material handling systems can improve accuracy and quality and increase productivity while reducing shipping times and labor costs. In particular, mobile robotic systems can ensure high accuracy and quality, improve worker satisfaction, address unique product needs, and mitigate large capital expenditures with modular, flexible implementation.

Amy Villeneuve is president and COO of Kiva Systems (Woburn, MA).

Sign up for the QMED & MD+DI Daily newsletter.

You May Also Like