Understanding the basics of perpetual and periodic inventory in the operating room

In a recent meeting with a chief financial officer (CFO), we tackled the challenge of optimizing inventory management in the operating room (OR). In the high-stakes environment of an OR, maintaining an accurate inventory of supplies is vital. Inefficient inventory management can lead to stockouts, surgical delays and overstocking, resulting in unnecessary waste. Choosing the right inventory methodology ensures that healthcare providers can maintain operational continuity, improve supply chain efficiency and support better patient outcomes.

We discussed two options: the simpler, lower-cost periodic or PAR inventory methodology, and the more advanced perpetual inventory system. The perpetual and periodic inventory methodologies each have advantages and disadvantages depending on the size of the healthcare organization, available technology and the specific demands within the OR.

A perpetual inventory system tracks supplies in real time using barcode scanning, radio-frequency identification (RFID) and similar technologies. While it requires upfront investment, it enables automated replenishment and ensures critical surgical items are available. As items are used, the system updates inventory levels, giving supply chain teams continuous visibility to anticipate shortages and prevent stockouts. Alerts can be triggered when stock falls below set thresholds, helping avoid disruptions during unexpected spikes in demand.

The periodic inventory method relies on manual counts at set intervals, such as daily, weekly or monthly, without real-time visibility. This delay can lead to overstock and stockouts. Spikes in usage often go unnoticed until the next count, unless flagged by OR staff, increasing the risk of supply shortages.

Four key dimensions: cost, implementation and maintenance, visibility and efficiency

When comparing perpetual and periodic inventory methods, it’s helpful to evaluate four key dimensions: cost, implementation and maintenance, visibility, and efficiency. This comparison highlights the strengths and limitations of each approach. The visual below can be used to support the selection of the most effective inventory management methodology for an organization.

Short-term benefits

• Perpetual inventory: Provides immediate insight into stock levels through advanced technology like barcode scanning and RFID, reducing the risk of stockouts and ensuring procedures continue without delays caused by missing supplies. The integration of technology streamlines inventory tracking, allowing for real-time updates and quicker response to supply needs. And integration of the perpetual system with the electronic medical record (EMR) ensures accurate and timely patient billing for supplies.

• Periodic inventory: Requires a lower initial investment in technology, as it does not rely on expensive automated systems. Its simplicity, minimal training requirements, and lack of dependency on IT for integrations make it an easy and accessible option, particularly for facilities where periodic methodology is already in use.

Long-term benefits

• Perpetual inventory: Over time, perpetual systems provide significant advantages, including waste reduction by preventing overstocking, improved budgeting accuracy and access to detailed analytics. These systems rely on advanced technology and cycle counting to ensure inventory levels remain accurate for replenishment, making them particularly valuable for hospitals with high turnover in OR supplies.

• Periodic inventory: While offering fewer long-term benefits, periodic inventory systems are easy for less experienced staff to adopt and require minimal IT support. This approach relies on manual counts to generate replenishment requisitions in the inventory system, often adding extra documentation steps in the EMR.

Foundation for successful inventory management in the surgical setting

Effective inventory methods in surgical settings rely on four foundational elements:

1. Partnership: Surgery and supply chain teams must be well partnered and aligned to meet inventory and service goals.

2. Accurate item master: The item master must be fully updated, complete and accurate to avoid discrepancies.

3. ERP system accuracy: Pricing and inventory data in the enterprise resource planning (ERP) system should be precise, as this system serves as the single source of truth for the EMR.

4. Dedicated resources: Resources are allocated to oversee and manage the inventory, ensuring continuity and accountability.

Meeting these fundamental requirements sets a solid foundation for either inventory method and ensures greater reliability in the OR.

Requirements for successful perpetual inventory implementation

These core elements are needed for effective perpetual inventory implementation in the OR.

1. Collaboration: IT must partner with both surgery and supply chain teams to ensure strong alignment, seamless integration and effective support.

2. Real-time documentation: Documenting all supply usage in real-time allows for immediate tracking and adjustments.

3. Regular cycle counts: Scheduled cycle counts help verify inventory accuracy and identify discrepancies.

4. Efficient returns processing: All case cart returns are completed, including count incrementation.

5. Usage alignment: Preference lists must accurately reflect actual usage patterns to maintain accurate counts and reduce returns in the perpetual inventory.

6. Performance metrics: Key performance indicators, metrics and dashboards are readily available to track success and address any issues promptly.

Achieving the additional requirements when implementing a perpetual inventory system will ensure efficiency, accuracy and reliability in the OR.

Align inventory management strategy with organizational goals

Perpetual and periodic inventory methods each serve a role in healthcare. Periodic systems offer simplicity and lower costs, while perpetual systems deliver real-time visibility and greater efficiency, which is especially valuable in high-demand areas like the OR. Choosing the right method depends on the organization’s needs, resources and scale, with success relying on strong collaboration, accurate data and dedicated support.

Following our meeting, the CFO decided to implement a perpetual inventory methodology and allocate funds toward inventory management. The CFO determined that this was the best long-term solution for their health system. This decision underscores the importance of aligning inventory management strategies with organizational goals to enhance efficiency, reduce waste and support optimal patient care in the OR.