Developing measures to improve the traceability of contaminated food products across the supply chain is one of the key provisions of the 2011 FDA Food Safety Modernization Act (FSMA). In the event of a recall, FSMA requires companies to provide information about their immediate suppliers and customers—what is referred to as “one step forward” and “one step backward” traceability.
In this paper we implement the logic-based approach called answer set programming that uses inference rules to trace the flows of contaminated products—both upstream to the source of the contamination and downstream to consumer locations. The approach does not require common standards or unique product identifiers for tracking individual products. This elaborationtolerant method can accommodate changes in the supply chain such as: 1) the addition of new multiple product pathways; 2) consideration of multiple ingredients in a single product; and 3) multiple products with multiple pathways. We demonstrate this highly flexible methodology for pork and peanut products.