Travel Distance Calculation 

Use

The travel distance is calculated for the storage bin list. A storage bin list is a list of storage bins that are to be approached sequentially for a warehouse order.

Features

●      The system differentiates between horizontal (X and Y coordinates) and vertical movements (Z coordinates).

●      The total travel distance is the sum of travel distances that lie between the storage bins that lie next to each other on the list.

●      The system generates the list of storage bins from the warehouse order creation rules. The order is fixed, meaning the travel distance calculation does not sort the storage bin list.

●      For the movements, we assume that:

                            a.      The resource executes the horizontal movement first, meaning the resource first moves itself to the storage bin in a horizontal direction.

                            b.      The resource then executes the vertical movement, namely the movement to the storage bin and back to the outbound item. 

                            c.      The resource then moves itself to the next storage bin in a horizontal direction.

                            d.      The total travel distance in a vertical direction therefore corresponds to twice the Z distance of the storage bins to the floor (point of origin Z = 0).

For the horizontal movements, a difference is made between:

●      Direct movements

The system uses the direct distance:

○       For movements between storage bins within a storage type, if no valid storage-type-specific network is available.

○       For movements between storage bins from different storage types, if no global valid network exists.

○       Movements within an aisle. Here, the direct distance between storage bins is used to calculate the travel distance.

The figure shows examples for travel distances between multiple storage bins within an aisle. The green line corresponds to the Euclidean metric, the dotted blue line represents the Manhattan metric.

○       For the connection of a storage bin with the network:

■       With the nodes of an edge, if the storage bin is in an aisle, and an edge exists for these. Fundamentally, four options exist. For a one-way route, only one option is allowed: entering the edge at the start node and leaving it at the end node.

The figure shows examples for the connection of a bin sequence within an aisle with the nodes of the respective edge.

 

■       With the next node, if no edge has been assigned (the node comes from the storage-type-specific network, or if this does not exist, the global network)

●      Movements within a network

These take place if the storage bins:

○       Lie in the same storage type but not in the same aisle, and a valid storage-type-specific network exists.

○       Are in different storage types and a valid global network exists.

For the calculation within the network (valid global and any existing valid storage-type-specific networks), the system connects the storage bins:

○       With the nodes of the respective edge or with the next node first 

○       Then the travel distance within the network between the storage bins is added to the assigned nodes. For this, a maximum of four options are available (if both bins can be assigned to one edge respectively (no one-way routes): from the start node of the first edge to the start node of the second edge, from start node to end node, from end node to start node, and from end node to end node).

The figure shows the different connections between edges (black line), edge and node (black dot), and nodes of a network (green line). The system uses the option that represents the shortest travel distance.