Table 1 Functional area calculation table.

Loading and Unloading Area

\(\:{S}_{1}=\frac{{Q}_{1}\text{*}{s}_{a}}{{T}_{1}\text{*}{p}_{a}}\:\) (1)

Express Temporary Storage Area

\(\:{S}_{2}=\frac{{Q}_{2}\text{*}{v}_{b}}{{p}_{b}}+{S}_{b}\) (2)

Primary Sorting Area

\(\:{p}_{c1}=\frac{{Q}_{3}}{{T}_{3}}\) (3)

\(\:{S}_{3}=\frac{{Q}_{3}}{{p}_{c2}}\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\) (4)

Small Sorting Area

\(\:{S}_{6}={S}_{d1}+{S}_{d2}\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\) (5)

\(\:{Q}_{e}={p}_{e1}-{p}_{e2}\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\) (6)

Comprehensive Office Area

\(\:{S}_{7}={U}_{f1}\text{*}{s}_{f1}+{U}_{f2}\text{*}{s}_{f2}\) (7)

Security Inspection Area

\(\:{S}_{8}={U}_{g}\text{*}{s}_{g}+{S}_{g}\) (8)

Packaging and Processing Area

\(\:{S}_{9}={U}_{h}\text{*}{s}_{h}\) (9)

Storage Area

\(\:{S}_{10}=\frac{{Q}_{10}\text{*}{v}_{i}}{{p}_{i}}+{S}_{i}\) (10)

Other Functional Areas

\(\:{S}_{11}={U}_{j}\text{*}{s}_{j}+{S}_{i}\) (11)

\(\:{Q}_{1}\)represents the logistics volume of a single loading and unloading operation;

\(\:{s}_{a}\)is the required area for a single loading and unloading platform;

\(\:{T}_{1}\)is the specified time for a single loading and unloading operation;

\(\:{p}_{a}\)is the loading and unloading efficiency of a single loading and unloading platform;

\(\:{Q}_{2}\)represents the average storage volume of the temporary storage area per unit time;

\(\:{v}_{b}\)denotes the space occupied by a unit storage volume;

\(\:{p}_{b}\)is the storage space efficiency per unit area;

\(\:{S}_{b}\)refers to the area required for other functional devices;

\(\:{p}_{c1}\)represents processing efficiency per unit time;

\(\:{\:Q}_{3}\)represents the logistics volume of the stage sorting operation;

\(\:{T}_{3}\)represents the specified time for the stage sorting operation;

\(\:{p}_{c2}\)represents the efficiency of parcel processing per unit area under the device selection scheme for achieving\(\:{p}_{c1}\);

\(\:{S}_{d1}\)denotes the area of the sorting operation zone, calculated in a manner identical to that of the primary sorting zone;

\(\:{S}_{d2}\)signifies the area of the unpacking zone, computed using the same method as for the parcel temporary storage zone;

\(\:{p}_{e1}\)represents the efficiency of logistics input;

\(\:{p}_{e2}\)represents the efficiency of sorting and supply;

\(\:{U}_{f1}\)represents the average number of office personnel per unit time;

\(\:{S}_{f1}\)is the per capita office space, typically taken as \(4.5\sim 7m^{2}\);

\(\:{U}_{f2}\)denotes the number of information system devices;

\(\:{S}_{f2}\)is the area occupied by each device, generally set at \(4.5\sim 5.5m^{2}\);

\(\:{U}_{g}\)represents the number of security checkpoints;

\(\:{s}_{g}\)is the area required per unit security checkpoint;

\(\:{S}_{g}\)is the area of the emergency isolation zone;

\(\:{Q}_{10}\)is the design storage capacity of the storage area;

\(\:{v}_{i}\)is the space occupied by a unit of storage;

\(\:{p}_{i}\)is the storage space efficiency per unit area;

\(\:{S}_{i}\:\)is the area required for other functional equipment;

\(\:{U}_{j}\)is the number of equipment (or personnel) required for the functional area;

\(\:{s}_{j}\)is the area required per unit of equipment (or personnel);

\(\:{\:s}_{i}\)is the area required for other functional equipment.