Fig. 5 depicts the facility scheme, which offers
a way to structure a logistic system. This scheme
is adapted from Evers (1994) and is related to the
seven-layer OSI model. Generally, a logistic system
consists of three primal layers:
1. externally received products and raw materials
to be subjected to a logistic operation;
2. handling units, indicating different internal
representations of product units, such as containers,
batch size and individual products;