This chapter introduces the concept of an electronic trade scenario as an aid to the management of (global) supply chains, and other forms of international, business-to-business electronic commerce. The problem addressed is the following. Competition demands that trade transactions be handled efficiently and securely. However, the same competitive environment also demands flexibility, and the ability to redesign the supply chain as conditions change. Current EDI (electronic data interchange) technologies offer efficiencies, but tend to be quite inflexible, often requiring substantial reprogramming for each modification to the transaction. Furthermore, these revisions need to be made not just for a single company, but for every affected company in the supply chain. In cases where some of the companies in the chain are relatively small, with limited computing staff and skills, such changes are even more difficult and disruptive. Electronic trade scenarios are generic, reusable models of the entire trade transaction. They are stored in a on-line repository, where each member of the supply chain can download the transaction component for their role in the transaction. In our proposed solution, the procedural logic of the transaction is designed using a high level, graphical representation called Documentary Petri Nets (DPN). The InterProcs system is described as a prototyping environment to support the design and execution of such supply chain transaction models using this DPN representation. A key concern will be the development of trustworthy trade scenarios that have sufficient controls and evidentiary documentation. Various directions of further work are described to improve the quality and flexibility of trade scenario designs.