On the structure of capacitated assembly systems

We consider a finite-horizon inventory model with an assembly structure, stochastic demand, and capacity constraints throughout the system. We explore optimal behavior of this system, with a special focus on stockpiling and stock-withholding of inventory, two novel inventory phenomena that arise due to asymmetric constraints. We identify conditions, such as having the bottleneck at the most downstream stage, that restore structural symmetry to the problem. This allows the state space to be collapsed to that of an equivalent series system.