In this paper, we discuss the design and optimization of supply chains at Dow AgroSciences. We start by introducing the design components of a typical supply chain. We then discuss the typical inputs required in a model and the type of outputs generated. Next we consider the strengths and weaknesses of the standard tools that we use as part of the model process. To show the breadth of problems addressed, three example models are presented. The first problem discusses the complexity of addressing a global supply chain for a new active ingredient. The second problem focused on a regional supply chain. The final problem showed a tactical model looking at rail fleet sizing. (C) 2018 Elsevier Ltd. All rights reserved.