A hierarchical production planning structure enables manufacturing systems to handle customer disturbances with different measures on different planning levels. Two different kinds of customer order behavior can be observed and are as well discussed in literature. In the first, being forecast-evolutionbehavior, customers provide a forecast quantity for a specific due date for a long horizon in advance and update their forecast quantities periodically. In the second, being customer-required-lead-time-behavior, customers demand stochastic order amounts with a customer-required-lead-time whereby the manufacturing company generates an aggregated forecast, e.g. for product groups. These required lead times are usually shorter than the forecast-evolution-horizon, but order quantities do not further change. For comparing the influence of both order behaviors on a hierarchical production planning system, a simulation study is performed in which logistic performance measures such as service-level, utilization, capacity-, inventory- and tardiness-costs are analyzed with respect to a normalized forecast quality measure.
Figure 1: Hierarchical Production Planning approach