Papers

Today's distribution and transport logistics suffer from significant inefficiency  factors mainly due to lack of resource and infrastructure sharing. According to some recent studies, the current transportation efficiency is in the neighborhood of 10%.  In the traditional commodity supply chain delivering fresh food, trucks often go either empty (to return the truck and/or driver to their home location) or partially empty (due to unavailability of suitable product or perishability concerns of the carried food). This leads to largely avoidable distribution costs, transportation carbon footprint, road congestion, delivery delays, etc. Yet, a significant percentage of fresh food is wasted due to real or perceived spoilage or loss of quality of fresh food from farm to the end customer. This paper exploits the ongoing technological developments to devise a mechanism for distributing perishable food packages while at the same time minimizing the empty miles to improve the fuel-efficiency.

One major obstruction to improving efficiency and decreasing food waste is the lack of universal sharing of logistics, particularly among the large vendors. However, the improving technology and the pressures to reduce cost are resulting to rapid growth of 3rd party logistics (3PL) and its derivatives such as 4PL which already account for more than 54% of the distribution logistics. 3PL involves outsourced logistics services using shared resources (warehouses, trucks, drivers, loading/unloading equipment etc.) and can achieve significant savings. Another key obstructions of logistics is the need to find drivers, ensure that they do not drive for more than the safe period, and get them home most nights. 

In this paper, we introduced the notion of a worker-friendly, "fresh food physical Internet (FFPI or F$^2\pi$)" architecture and explored the mixing, packaging and delivery of food packages in different parts of the food pipeline. With food sourced from every part of the country and from around the world, food supply chains are extremely complex pathways from farm to the table. Health concerns have prompted a rapid rise in the demand and consumption of fresh fruits and vegetables, with consequent emphasis on cost effective supply of freshest food to the consumer. The sustainability concerns and local food movement have further emphasized the issues of freshness, quality, intelligent sourcing, and most cost effective transportation of perishable food items. The distribution process of perishable food commodities follow extremely complex pathways from their origins to the consumption points, due to their constant deterioration with time, which makes the modeling and improvement of such logistics extremely difficult.

In a similar note, physical Internet has been studied recently that attempts to revolutionize product distribution logistics by emulating the Internet. The key issues in making the distribution logistics more efficient, flexible, cheaper, and more user friendly include (a) standardization of identification, labeling, packaging, transportation, tracking, etc, (b) sharing of physical distribution infrastructure among multiple companies, and (c) worker friendly logistics (e.g., enabling truck drivers to return home for the night). While the architecture of physical Internet introduces a number of key characteristics, the requirements of food freshness remained untouched. The key characteristic of F$^2\pi$ is the constant deterioration in quality of a food packages based on the delay in the distribution pipeline and handling factors such as temperature, humidity, vibrations, etc. In this paper our key objective is to extend this physical Internet model to address the distribution challenges of "food logistics". We first develop a "freshness" metric of different food products as a function of flow time through the logistics system.  The deterioration as a function of time $t$ can be described by a non-decreasing function that we henceforth denote as $\zeta(t)$. In general, $\zeta(t)$ is linear for fruits or vegetables and exponential for fish/meat. The decay itself is a complex phenomenon and could refer to many aspects, including those that can be directly detected by the customers (e.g., color, texture, firmness, taste, etc.) and those that are latent but perhaps even more important, such as degradation of vitamin content or growth of bacteria. Furthermore, the decay rate is strongly influenced by the environmental parameters such as temperature, humidity, vibration etc.

Another key concept addressed in this paper is the notion of "infrastructure sharing" among the different agents in the food pipeline. In the traditional supply chain, the trucks often go almost half-empty in the delivery process, which increases distribution costs, transportation carbon footprint, road congestion, delivery delays, etc. Furthermore, it appears that most major companies use their own private logistics network including trucks, warehouses, etc. Although smaller companies seem to be using 3rd party logistics (3PL), it is not clear if there is really a true sharing of capacity among them -- as opposed to each reserving and paying for capacity explicitly. A true pooling of resources (warehouses, trucks, drivers, loading/unloading equipment and personnel, etc) can achieve significant savings. However, there are numerous issues that come up in cooperative logistics, due to the additional complexity of sharing of equipment (trucks, forklifts, RFID infrastructure, etc), facilities (distribution centers, chillers), and personnel (truck drivers, loading/unloading personnel, RFID trackers, etc). These, in turn result in complex problems of assignment, scheduling, personnel welfare, disposal of spoiled food, equipment/facility maintenance, etc. 

We also explore the idea of shared logistics to "reduce trucker's time away from home", by dividing the long journey of a truck drivers among multiple drivers. The idea is to divide the entire operational area into multiple zones driven by the locations of distribution centers, and limit a truck run to within a zone only. The inter-zone delivery requires multiple trucks run with each driver returning back to its source after passing on the contents to the next truck across the zone boundary. Ideally, the returning truck will also carry compatible products in the other direction. This requires rather close cooperation and interactions among the agents in the food pipeline, that are used to work in isolation. The continuous perishability of the food products further complicates the matter. We believe that the proposed F$^2\pi$ architecture will complement the existing efforts of emulating the digital Internet into the traditional logistics networks. Even if we address this in the context of fresh food logistics, our methodology is generic enough to be adapted to other logistics systems as well.