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Enhanced Logistics Tracking
and Monitoring Through
Sensor Technology

During peace and in war, the U.S. Army loses millions of dollars annually to spoilage, mishandling, and theft of supplies while in transit and in storage. In Southwest Asia, medical sets awaiting transportation from the airfield can be exposed to temperatures of over 120 degrees Fahrenheit. Soldiers using those medical sets conduct visual inspections, but they cannot be certain how long the items were exposed to high temperatures and whether or not they remain viable. Each year, the Army destroys a significant amount of valuable medical materiel because of the unknown effects of environmental conditions that it endured.

Destroying medical materiel increases medical costs on the battlefield and affects patient care. Many of these losses could be mitigated with automated sensor technology that monitors and reports on the condition of environmentally sensitive assets. The ability to monitor the condition of assets in austere environments makes it possible to determine if those supplies can be safeguarded and delivered in serviceable condition for the Soldier. With the development and use of microelectrical mechanical systems (MEMS) sensors integrated with radio frequency identification (RFID) technology, Soldiers can now automatically capture and report critical environmental and security information.

Radio Frequency In-Transit Visibility

During Operations Desert Shield and Desert Storm, thousands of containers had to be opened, inventoried, resealed, and reinserted into the transportation system because logisticians did not have visibility of their contents. The volume of materiel moving through the logistics pipeline far exceeded the Army’s ability to track materiel, maintain accurate records, and provide timely information to commanders. As a result, the receiving ports and container yards became “iron mountains” of containers filled with undocumented supplies and equipment.

Realizing that an automated solution was required, the Army began testing commercial off-the-shelf active RFID tags to track supplies. RFID tracking devices were installed throughout the supply chain in locations like military and commercial air and sea ports, supply depots, and warehouses. The Army now has a robust worldwide infrastructure that includes a radio frequency in-transit visibility (RF–ITV) server that collects RFID data and stores, processes, and distributes asset location and “in-the-box” identification information.

Over the past few years, the RF–ITV infrastructure has expanded rapidly to meet the needs of deploying expeditionary forces. Since the beginning of the Global War on Terrorism, the worldwide RF–ITV infrastructure has quadrupled in size and currently has 4 regional servers and more than 4,000 read-and-write sites located in 40 countries. The RF–ITV servers allow users to track shipments, observe activity at a specific location or site, determine the operating status of RFID interrogators, and obtain RF–ITV metrics and statistics over selected periods of time. Integrating active RFID with MEMS sensor-based environmental condition monitoring technologies adds a third dimension of asset visibility to augment identity and location recognition.


The Army recently conducted condition monitoring demonstrations to test the effectiveness of MEMS RFID specifically for—

  • The long-term storage of assets in deployable medical systems (DEPMEDS) at Sierra Army Depot, California.
  • In-transit nodal monitoring of medical sets, kits, and outfits (MESKOs) that are shipped from the U.S. Army Medical Materiel Center-Europe (USAMMCE) depot in Pirmasens, Germany, to customer destinations in Iraq and Afghanistan.
  • In-transit security monitoring of Defense Logistics Agency containers with class I (subsistence) items that are shipped from facilities and ports in the United Arab Emirates to Afghanistan in support of U.S. and coalition forces in the U.S. Central Command (CENTCOM) area of operations (AO).

Long-term storage monitoring. DEPMEDS hospitals hold medical materiel and associated hospital equipment. They are also used for transportation and provide functional workspace for clinicians. The DEPMEDS are stored outdoors at Sierra Army Depot in 20-foot deployable military vans and expandable tactical shelters until needed for deployment.

The Army Logistics Innovation Agency, the field operating agency of the Army G–4, tested the use of MEMS RFID for DEPMEDS at Sierra Army Depot at the request of the Army Materiel Command and the Army Tank-automotive and Armaments Command, in collaboration with the U.S. Army Medical Materiel Agency (USAMMA). The intent was to assess the capability of MEMS RFID to monitor the environmental conditions to which DEPMEDS were exposed and extrapolate the results to guide decisions on further testing or actual fielding of MEMS RFID.

Before MEMS RFID, condition monitoring at Sierra Army Depot consisted of labor-intensive monthly visual examinations of containers and inspections for deterioration of seals on the expandable containers. The inspections were necessary because exposure to high humidity and extreme temperatures for long periods of time can affect the mission capability of stored medical equipment or result in the loss of that equipment.

Throughout the demonstration, MEMS RFID sensors collected and stored hourly readings of temperature and humidity data in the containers. Whenever established environmental thresholds were exceeded, notifications were automatically sent to Sierra Army Depot and USAMMA users. During the demonstration, MEMS RFID provided the ability to view DEPMEDS environmental data remotely and receive automatic alerts of high and low temperatures or humidity conditions. Automated MEMS RFID readings provided significantly more accurate and reliable humidity data than visual readings.

In-transit nodal monitoring. USAMMCE manages the assembly, disassembly, and reconstitution of MESKOs, which consist of medical products, including items that are vulnerable to extreme environmental conditions such as temperature or humidity. MESKOs are packaged according to the projected environment of the destination region. However, USAMMCE’s process lacked a method for monitoring environmental data that would help Soldiers make informed decisions on the longer term viability of assets. For the USAMMCE MEMS RFID demonstration, which was conducted by the Army Logistics Innovation Agency and the Product Manager Joint-Automatic Identification Technology (PM J–AIT), an ST–674 sensor tag was placed inside each MESKO to monitor, record, and transmit data on environmental factors that influence the operational service life and condition of the assets.

PM J–AIT integrated a commercial sensor application with the RF–ITV server and upgraded the ITV network nodes with sensor read capabilities along the demonstration’s distribution routes from USAMMCE to final destinations in Iraq and Afghanistan. When a temperature parameter or shelf-life timer was breached en route or in storage, an alert was sent automatically to USAMMCE users through the RF–ITV network. The alert notified USAMMCE of the unacceptable environmental condition and the time and nodal location of the event. The demonstration showed how MEMS RFID is suitable for onward shipment and use and supports proactive management through asset viability.

In-transit security monitoring. Sensor tags can also be used to detect intrusion. Prompted by incidents of active RFID tags being destroyed, damaged, and stolen from containers without command knowledge, PM J–AIT conducted a limited operational test in the CENTCOM AO of the new ST 675–I security sensor container tag. In addition to temperature and humidity condition sensors, the ST 675–I tag monitors container security by using open door, light, and shock sensors while the container travels along the supply chain. The ST 675–I checks, time-stamps, and logs door security status and environmental data at frequent intervals using local flash memory. During the demonstration, the tag beaconed and transmitted alert messages to the RF–ITV network whenever an alert event occurred. The test successfully demonstrated the potential for sensors to enhance container security.

The Next Steps

The demonstrations at Sierra Army Depot and USAMMCE and in the CENTCOM AO have paved the way for future MEMS and sensor tag implementations. The demonstrations validated the use of sensor-enabled RFID technology for automated in-transit and in-storage condition and intrusion monitoring.

Although the demonstrations focused on specific assets that show possible high-payoff applications of MEMS RFID, the benefits of sensor technology extend to all classes of supply and logistics processes and across all services. Clearly, these capabilities are particularly appropriate for life-limited assets, such as medical supplies and food, but the applications are many and varied and each application must be evaluated based on individual merit. Key considerations for implementing the technology include examining business rules, integrating the supporting automated information systems, establishing policies and standards, and developing training programs for the schoolhouses. As sensor, RFID, and satellite-based location and tracking systems become more interoperable, these sense-and-respond networks will help improve the quality, integrity, and safety of products in storage and in transit.

Currently, PM J–AIT is working to integrate MEMS RFID technology into the RF–ITV infrastructure so that users can view the identities, locations, and conditions of their shipments. This will support improved readiness by increasing visibility and providing tools to ensure the efficacy of life-limited Army assets. USAMMCE is continuing to use the capability. The Army Materiel Command is working with PM J–AIT and USAMMA to implement active RFID container security sensor tags in all DEPMEDS in storage at Sierra Army Depot. The medical community is exploring the use of sensors and associated alert capabilities for monitoring refrigerated shipments and medical chemical defense materiel. The Army Medical Department is collaborating with PM J–AIT, Army G–4, Army Central Command, and other stakeholders to identify requirements for fielding, sustainment, and user training.

Using MEMS RFID is an effective way to reduce or eliminate losses caused by extreme environmental conditions and security issues. MEMS RFID provides logisticians a unique opportunity to transform the logistics process by providing more timely and accurate support to Soldiers. As the technology becomes more widespread, it will allow logisticians to gain near real-time situational awareness, giving them the ability to make responsive decisions based on timely, condition-based information. As a result, Soldiers will have greater confidence in the viability of their assets, and logisticians can improve packaging techniques, learn more about environmental effects on assets, and deliver serviceable supplies more quickly.

Janina W. Plinsky is a logistics management specialist for the Army G–4 Logistics Innovation Agency and the project leader for the microelectrical mechanical systems demonstrations. She is a graduate of Kansas State University and has a master’s certificate in project management.

Jerry Rodgers is a senior project manager for Innovative Logistics Techniques, Inc., and a support contractor for the Product Manager Joint-Automatic Identification Technology. He has a master’s degree in business administration from the Florida Institute of Technology, and he is a graduate of the Army War College.