Implementing and Optimizing Carousel Technology

March 2014 - Vol.11 No. 3 - Page #22

Medication errors are a leading cause of mortality in the US, and dispensing errors account for approximately 21% of all medication errors, with most of these errors occurring in the administration phase.1 To improve patient safety and operational efficiency, technology is available that spans the entire medication-use process. Utilizing medication carousels to improve medication storage and dispensing can increase safety and enhance pharmacy workflow. Carousel use is increasing in popularity in US health systems; Pharmacy Purchasing & Products’ 2013 State of Automation Survey revealed that while few small hospitals utilize carousel technology, 60% of hospitals with 400+ beds have chosen to automate their medication storage using carousel or robots.2

Tufts Medical Center (TuftsMC) is a 420-bed, stand-alone tertiary care academic medical center with a level 1 trauma center. The TuftsMC pharmacy department is structured around decentralized clinical pharmacy services in cardiology, critical care, oncology, general medicine, and pediatrics/perinatal services. More then 80% of the doses are stored in automated dispensing cabinets (ADCs), which serve as the primary method for medication distribution. The pharmacy department processes over two million medication doses annually. As part of a highly automated hospital, the TuftsMC pharmacy department has incorporated technology into most phases of the medication-use process over the past five years, including computerized prescriber order entry (CPOE) systems, clinical decision-support systems, biometric/bar code–driven ADCs, bar code medication administration (BCMA) devices, and smart pumps. However, carousel technology was missing in the dispensing phase of the medication-use process. In an effort to fully automate medication dispensing, the pharmacy department recently implemented carousel technology to meet the goals of improving medication safety, increasing technician efficiency and accuracy, reducing space requirements for medication inventories, and ensuring cost savings.

Prior ADC Restocking Process
Prior to implementing carousels in 2012, our ADCs were replenished via a manual process whereby pharmacy technicians walked the shelves and then refilled ADCs based on predetermined inventory levels. Medications in the pharmacy were stored alphabetically and all three technicians walked the stockroom to fill their own lists. This process required the three technicians to dedicate 1.5 hours each to compile the medications, another hour to pull pediatric doses, and 1.5 hours for the pharmacist to verify the medications (seven hours total). Clearly, this process was grossly inefficient given the redundancy of three technicians pulling the same medications for different areas; in addition, no added safety measures were provided within the dispensing step of the medication-use process. 

Choosing Carousel Technology
Carousels support a systematic approach to ordering, stocking, picking, dispensing, and replenishing ADCs, and allow for just-in-time inventory management and an increase in inventory turns. Most importantly, carousels support bar code technology to ensure medications are stored in the correct bins, and increase safety, given the interfaces to the ADCs. Data suggests that carousel technology with bar code scanning can significantly reduce dispensing errors.3 In addition, carousels improve pulling times for ADC stocking, allowing technicians to be redeployed to other tasks; improve organization of medications based on utilization; and increase the ability to distinguish high-alert medications and look-alike/sound-alike medications through use of color-coded bins. 

The evaluation and installation of carousel technology was conducted in several phases: securing funds, conducting a functional needs assessment, redesigning the pharmacy, carousel installation, building the carousel, redesigning workflows, staff training, and carousel optimization; all were important components of our comprehensive carousel implementation process. 

Most business plans for carousel implementation focus on labor reduction, inventory reduction, and/or safety improvements. At TuftsMC, rather than justifying our need for the carousels, we leveraged our wholesaler contract. When it was time to renegotiate our wholesaler contract, we requested that the carousel technology be incorporated into the overall deal structure. 

Functional Needs Assessment and Pharmacy Redesign
Meaningful practice redesign must begin with a thorough understanding of the patient-care process and identification of the practice-specific strategies for improving efficiency. The choice of methodology depends on the nature of the performance patterns or desired process improvement. While it is key to incorporate functional needs and processes into the design to support operations, this can be challenging, mainly due to the limited literature available on how to achieve an optimal layout design for a pharmacy. Although some core principles exist, they are not always relevant to the field of health care, or to the specific practices in a given pharmacy.

One way to take the complexities of this environment into consideration is to perform a requirements analysis, or functional needs assessment, prior to redesign to identify the various requirements, as well as to collect data to improve quality. Our needs assessment took numerous factors into consideration, including the location of the carousels, minimization of steps needed to complete major workflows, placement of the pharmacist workstation and checking area, and staffing patterns required for effective oversight of operations. For example, on overnights, two pharmacists are required to oversee the replenishment of over 50 cabinets and the sterile product area. 

A pharmacy remodel is often necessary to make room for a new technology implementation. Extensive planning must be undertaken to ensure success, and this stage is particularly critical when the redesign encompasses the greater pharmacy and includes workflow reengineering. To ensure adequate space for the carousels, we found the assessment and planning stages were the two most critical phases.

The pharmacy remodel was completed over a seven-month period; during this time, the pharmacy remained operational, but utilized fewer workstations. Day-to-day dispensing was augmented to allow pharmacy activities to continue. Tools such as spaghetti maps, process flow maps, and relationship diagrams are often suggested as a good starting point to gain an understanding of a facility’s needs. We found spaghetti diagrams helpful in studying the traffic flow patterns established prior to the carousel implementation, as they provide insight on how the workflow related to the facility design, the location of resources, and the traffic flow between different areas (see FIGURE 1). The diagrams clearly indicated that we needed to identify strategies to relieve congestion in the new pharmacy redesign (see FIGURE 2). The spaghetti diagrams exposed the inefficiencies in the layout—illustrating instances where staff members had to travel long distances to complete a single task, for example. 

Another factor we considered was how to allocate sufficient storage space for medications and the approximate square footage needed for the two 36-shelf carousels with the capacity to house over 2000 line items (including bulk medications, unit-dose tablets, capsules, liquids, injections, ophthalmics, and other multiple-dose preparations). 

Building the Carousel
It was critical to determine the quantity of inventory that could be moved into the carousels, diagram the physical layout, and determine medication inventory levels using historical data based on utilization, not purchases. We determined that all medications could be moved into the carousels within two to three days. The configuration for the two carousels was important: we decided to include multiple workstations, and not daisy chain, or connect, the two carousels, so that multiple individuals could utilize the carousels at the same time. Medications were assigned into the carousel using the software to create individual bins. To ensure each medication would then fit into the designated bins, we drew diagrams of where every medication should be placed based on height, width, and weight.

When assigning medications as line items, ensure your medication list is complete. Minimum and maximum par levels also must be accurate and based on utilization rather than historical purchases. In addition, assign medications appropriately to minimize spinning, while simultaneously considering a balance of weight. Once built, we utilized reports within the software to ensure that the medications were assigned to the appropriate shelves based on utilization in order to maximize efficiencies by decreasing the number of rotations (see FIGURE 3). 

One unique element of our carousels is that they house both unit-dose and bulk medications. The carousels are configured as a combination of medication storage and ready-to-dispense items. Oral medications, such as tablets, capsules, and suspensions that come from the manufacturer in bulk packaging, are stored in the carousel, and a report is run daily to identify which products need to be repackaged into ready-to-administer doses. All satellite items are housed in a single carousel to further simplify the dispensing process. In addition, we have utilized the software to maintain a perpetual inventory in satellite areas, such as the sterile products areas and the OR pharmacy. 

Gaining staff buy-in and ensuring proper training occurs were key steps in our transition to carousels. We chose to begin the training early in the process, while also encouraging staff to embrace change. Two workgroups were formed, including managers and end users, to define new expectations, and a staff training manual was developed. Staff was introduced to their new responsibilities, including cycle counts, completing the training checklist, one week of carousel training, working with superusers, and honing skills using a tech-train-tech and a pharmacist-train-pharmacist program.

The carousel workflow and time required to complete tasks was reviewed and incorporated into the training process (see FIGURE 4). This workflow helped to anchor the change and outlined the roles of staff utilizing the carousels. Staff was also expected to complete a training checklist that outlined the core competencies required to operate the carousel. We spent the first six weeks shadowing staff to ensure competency. In the post-implementation phase, it became important to address individuals’ concerns and emphasize that the new technology will change their job functions, not replace their jobs.

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Results and Future Goals
The safety benefit afforded by bar coding—as medications are scanned going in and out of the carousels—was among the greatest returns from our carousel adoption. In addition, since the carousels were implemented, we have been able to demonstrate a cost reduction of about $400,000 to the c-suite. This is primarily due to a decrease of on-hand inventory and increased inventory turns. Increased efficiencies include improved workflow and time savings for technicians, the ability to pull medications during the night shift, and the ability to repackage in-house (using an automated report to identify items that require repackaging). 

The investment in carousel technology has allowed us to redesign workflow in the central operations to allow for the deployment of technicians to perform patient-centric, as opposed to product-centric, tasks. Also, it has improved overall inventory management by increasing inventory turns and decreasing stock-outs.  

We are now in the process of optimizing the locations and inventory levels of medications stocked in the carousel to decrease stock-outs while maintaining appropriate inventory turns. The goal is to integrate the top 25% of items on shelves that are in close proximity to decrease carousel rotation while maintaining weight balance on the shelves. 

Various carousels offer different reports to assist with inventory optimization. We are reviewing a number of reports to help identify adjustments to minimums, maximums, and par levels. In addition, we are in the planning phase of implementing a first-dose interface with our pharmacy information system to add an additional level of safety for our patients and to increase efficiencies in central operations. The stat/first-dose interface will automate the picking of these medications by sending patient-specific information directly to the carousel from the pharmacy system. We anticipate that the interface will increase efficiencies with multiple stat/first doses and reduce the rate of miss-picks resulting from a manual process.


  1. Santell JP, Hicks RW, McMeekin J, Cousins DD. Medication errors: experience of the United States Pharmacopeia (USP) MEDMARX reporting system. J Clin Pharmacol. 2003;43(7):760-767.
  2. State of Pharmacy Automation Survey. Pharm Purch Prod. 2013;10(8):14-15.
  3. Temple J, Ludwig B. Implementation and evaluation of carousel dispensing technology in a university medical center pharmacy. Am J Health-Syst Pharm. 2010;67(10):821-9.

Grace Lee Herr, CPhT, is the lead certified pharmacy technician for pharmacy informatics at Tufts Medical Center (TuftsMC). She received her bachelors degree in business management from Johnson & Wales University and is currently in the health care analytics certificate program with plans to pursue an MBA.

Melissa Ortega, PharmD, MS, is the manager of acute care operations at TuftsMC. Melissa earned her doctorate of pharmacy degree from Nova Southeastern University in Fort Lauderdale, Florida and her MS in health-system pharmacy administration from The University of Wisconsin-Madison. 

Joan Calamari, RPh, the assistant director of pharmaceutical services at TuftsMC. She received her pharmacy degree from Northeastern University and completed a pharmacy residency at Northwestern Memorial Hospital.


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