â This book extends the existing demand fulfillment research by considering multi-stage customer hierarchies. Basis is a two-step allocation and consumption planning procedure. In the existing literature, it is assumed that the customer segments are `flat'. This means they can be sorted easily during the allocation planning step by a single central planner in decreasing order of profitability. In the subsequent consumption planning phase, if order requests differ in terms of profit margins, companies can render prioritized service in real time to their most profitable customers by consuming the reserved quotas.