Case Study: Global Cold Chain Management

Perishable Supply Chain is the market for all commodities that require temperature cold chain management and a controlled environment to transport these products to market. Perishable products include frozen and fresh food, pharmaceuticals, chemicals and many other specialty products such as flowers, root stock and plants. The perishable supply chain consists of many forms of transportation such as truck, train, ocean vessels, and airplanes that are interconnected through distribution points such as ports and warehouse distribution centers (figure below).

Perishable Supply Chain

Perishable Supply Chain

The market serves many constituents that work together in partnerships to move the commodities from the point of origin to destination with performance determined by:  cost, time, integrity of the cold chain, freshness at destination, safety and reliability.  A perishable supply chain for blueberries from Chile to Europe, as an example, will start with the farmer or grower, who contracts with an ocean carrier to transport from Chile to Europe.  The ocean carrier will arrange for a refrigerated cargo container (known by the trade name “reefer”) to be loaded on a truck carriage at the port and drive to the farmers location where it will load the blueberries into the reefer and the cold chain management will start.  The condition of the blueberries after they are harvested (post-harvest food science) will influence the results of the trip along with the type of packaging and other environmental effects along the route.  The trucker then leaves the farm and transports the product to the port where it is checked in and put in inventory while it is staged for loading onto the vessel.  During this inventory period and on the truck the reefer must be powered so it can maintain temperature.  The reefer is then unplugged and loaded on the vessel, with vessel turnaround times at port as short as possible to maximize the on ocean utilization of the ship.  The voyage to Rotterdam is about 30 days on ocean where the product is stored under temperature and atmosphere management.  For fresh food it is important, in addition to temperature management, to control the atmosphere in the container with a recipe that matches the commodity being transported.  The controlled or modified atmosphere helps preserve the freshness of the product through reduction of the rate of respiration of the food, reduction or elimination of mold and other plant pathogens, reduction or elimination of ethylene a hormone that induces ripening. Blueberries to stay fresh for this period of time require a higher level of CO2 along with other atmosphere modifications such as reduced oxygen levels or injection of ozone, scrubbing or oxidization of ethylene along with strict temperature control.  Once the reefer arrives in Rotterdam it is unloaded from the ship and placed back on a truck trailer for delivery to the importer where the berries are unloaded, inspected and then sorted and packaged for delivery to a retail outlet where the consumer can enjoy eating fresh blueberries in January six weeks after the berries were harvested. If there is a problem with the shipment a process of claims will start where insurance and other parties determine what caused the issue and who is responsible for remuneration.

The market for perishable supply chain is a multi-billion dollar global market.  The number of refrigerated containers exceeds 1 million and is growing at 4 to 5% a year.  The demand for fresh and frozen food on a year round basis is driving this market as people around the world improve their life style and demand a more nutritious fresher diet.  In addition the market is shifting from designated reefer ships which consisted of a few large refrigerated cargo holds to ships that carry reefer containers.  Post-harvest science and controlled atmosphere is also allowing a shift from the use of air cargo to ship fresh food to ocean reefer containers a much more economical and environmentally friendly method of transportation.

Functional Solution Overview

A high performing perishable supply chain requires 4 elements.

  1. Container Resource Planning (Forecast, Planning, Tasks and Performance Analytics) :  creates the ability to effectively utilize the fleet of refrigerated containers and provide the correct number of units at the right location at the right time for the commodities being shipped.
  2.  Equipment Performance MRO (Maintenance, Repair and Operations) :  assures that the reefer container is operational and will perform for an entire trip to maintain the perishable supply chain. During the trip the reefer and controller monitor and maintain the conditions required to assure the highest quality commodity is delivered.
  3. Cold Chain Management: The most critical factor in any perishable trip is consistent cold chain management and the system must provide monitoring, and control of temperature throughout the trip.
  4. Fresh Food Atmosphere:  a percentage of the perishable supply chain is the transportation of fresh food which requires a controlled atmosphere managed to a recipe to assure the highest quality freshest food is delivered.

This Case Study is based on the enterprise solution from Purfresh, which meets the requirements of perishable supply chain management through IntelliFleet TM, an innovative SAAS enterprise application, and Intelli-ReeferTM a controller built on an Industrial Internet architecture. This solution provides all four elements for successful perishable supply chain control:  Fleet planning, forecasting and operations management, maintenance, repair and operation (MRO), and intelligent cold chain management (ICCM). IntelliFleet provides the ocean and intermodal carriers an innovative technology for the transportation of perishable goods to market. The result is an economical and productive perishable supply chain solution that claims it will help solve the worldwide 50% food waste problem and allow ocean carriers increased productivity and margins.

One of the challenges for such a solution is that has to integrate with a complex logistics system which is already in operation and cannot be interrupted. Says Brian Westcott, PhD, CEO of Purfresh: “The way it works is a grower requests a trip with Purfresh through an ocean carrier.  By forecasting demand and working with long term contracts Purfresh estimates demand and prepositions controllers at the ports ready for installation.  Once a booking is scheduled a Purfresh agent installs the unit on a reefer (15 min process) and presses a switch to start communication (through satellite or GPS) and to synchronize with the IntelliFleet cloud software running in Amazons Cloud infrastructure. The recipe is downloaded for the commodity set in the booking and real time monitoring is initiated. During the trip the reefer is monitored through the IntelliFleet software and alarms are triggered if set-points or other events take place.”  A screen shot of a trip is shown in the figure below.

Real time Trip Monitoring

Real time Trip Monitoring

The systems has complete functionality to perform all the functions needed for high performing perishable trips using remote monitoring and control.

IntelliFleet system - Functionality

IntelliFleet System – Functionality

When implemented the IntelliFleet solution turns a static reefer fleet into an automated remote control and monitored or Intelligent reefer fleet.

Technical Solution Details and AIA

The IntelliFleet system consists of three main components shown in the figure below:

  1. Sensor network : the sensors monitoring temperature, operating parameters, and atmosphere parameters are both distributed throughout the container, embedded in the reefer ventilation system or embedded in the controller.
  2. Master Reefer Controller : The reefer controller provides two way communication to the IntelliFleet cloud application, and real time control of the actuators for atmosphere control including ozone generating units and venting valves.  The controller also provides real time data collection and storage which it uploads through satellite every two hours.  The controller also connects to the refrigeration controller and monitors and can communicate and change operating parameters of the refrigeration controller making it act as the master controller.
  3. IntelliFleet Enterprise software application: provides the organization a complete monitoring and control application for individual reefers as well as a complete fleet of reefers belonging to a company. IntelliFleet runs different instances for each company.

The figure below shows how these elements map to the Ignite | IoT Asset Integration Architecture (AIA).

Asset Integration Architecture for Intellifleet

Asset Integration Architecture for Intellifleet

Data is acquired in different time intervals based on the measurement.  Ozone and door open light sensor is measured every 1 second.  Temperature and CO2 readings are measured every 10 seconds.  Accelerometer and power off are measured on an interrupt basis and logged.  The atmosphere data is filtered over a ten minute period and then recorded as a filtered number for that interval.  Data is stored in the controller.  Communication with satellite is user selected but a normal interval that matches the dynamics of the reefer container is 2 hours.  At 2 hour intervals a packet of information that reflects the current state of the system is transmitted. Also at this time the controller can receive communication on new set-points to adjust operation of the system.  At the end of the trip or at any time during the trip when a GSM signal is acquired the complete trip information to that point is downloaded to the cloud and stored.

Lessons Learned and Recommendations

The following are the key lessons learned by the Prufresh team in working with their customers:

  • Sensors and Calibration – As in most control system the sensors are the most critical component with significant cost and maintenance linked to these devices. Calibration and maintenance of the sensors occurs every few trips.  There is constant review of more robust sensors as well as better faster ways to self-calibrate the system for reduced operating costs and increased robustness.
  • Communication Infrastructure – It is important in any system to be judicious in the acquisition of data making sure to time the measurements to the dynamics of the system being monitored and controlled. The communication infrastructure for this system can become expensive if excessive data is transmitted over satellite so the key to performance is filtering the data and transmitting enough information to accurately give the state of the system but not transmitting excessive data.
  • Cloud Computing – The inexpensive and reliable infrastructure available through a third party cloud computing environment has made the solution possible. As costs continue to decrease more information will be stored and analyzed to improve perishable supply chain performance.
  • Training – The human side of system performance cannot be neglected when converting to a more automated system with remote operation. Training becomes essential to the use of the system and confidence that it will provide superior service to the end customer.  Layers of training should be implemented including classroom type as well as one-on-on mentoring of operation of the live system.  Training should include ongoing support through a strong customer service group.
  • Diffusion of Innovation and organization change – The perishable supply chain is a complicated set of tasks requiring coordination of capital equipment. The system must be responsive to the variations caused by dealing with nature and biology.  Schedules can easily become late due to weather or other natural events.  The most difficult part of introducing any new innovation is changing the organization to work in a different way.  At first this will be uncomfortable and many people will find excuses on why the new system will not work correctly in this type of environment.  Change is not easy and most people resist change to some degree because they worry both that the customer will not receive the level of service that was previously delivered and that they as employees will not be able to adapt and learn the new skills necessary to operate a new system.

We would like to thank Brian J Westcott, CEO of Purfresh, for his contribution.