Introduction

Overview of logistigate

The logistigate methods infer rates of substandard and falsified products (SFPs) at locations within two echelons of a supply chain, using testing data only from samples of products at locations of the lower echelon.

Each location of both echelons has some fixed SFP rate. Non-SFP products traveling through a location become SFP according to this rate. All products travel through one location of each echelon. The probability of a lower-echelon location obtaining product from upper-echelon locations is stored in a “sourcing-probability matrix” for that supply chain. Product testing at the lower echelon is conducted with a diagnostic tool with a known sensitivity and specificity. Detection of an SFP is recorded as “1” and no detection is recorded as “0.” There are two types of supply-chain information settings available to regulators, Tracked and Untracked:

• In the Tracked case, both the upper-echelon and lower-echelon locations traversed by a product are known upon testing.

• In the Untracked case, the lower-echelon location where the product is obtained is known, as well as the system’s sourcing-probability matrix.

The paper proposing these methods is available on Arxiv at https://arxiv.org/abs/2207.05671 .

This work was funded through two National Science Foundation grants: EAGER Award 1842369 and NSF 1953111.