Section 7 Building area calculation
The location where a distribution center will be built is called its location, and various legal restrictions (location conditions) apply depending on the location. Even just looking at the City Planning Act, there are 13 uses, including residential, commercial, and industrial. Other factors, such as the Building Act, Fire Service Act, Radio Act, and coordination with neighboring residents, make site selection so complex that only experts can handle it.
Site area (or building area) is always required when selecting a site. Outsourcing this process requires time and money, and an additional in-house burden: a site survey (to set prerequisites for area calculations).
Tera Calculation 2 is software that teaches users how to calculate the area and size of logistics space from shipping data. To provide reference material for site selection, we have added software to calculate site area (building area). Please note that this calculation is a reference value only, not a final value. Please adjust the calculation based on other conditions and other documents to determine the final area.

Buildings can only be constructed using blueprints by qualified architects (class 1 and 2 architects); unqualified individuals cannot determine building specifications. However, we believe it is possible and necessary to have an idea of ​​the area and size of a distribution center. The building diagrams shown in Tera Calculation 2 are conceptual drawings, not blueprints. The building dimensions shown in Tera Calculation 2 are tentative and are used only to calculate approximate floor area.

Building Aspect Ratio
Tera Calculation 2 space area calculations do not have a concept of dimensions. Building dimensions are calculated by specifying the building's aspect ratio. Aspect ratios of 1:1 or 2:1 are rare, with rectangular distribution centers shaped like 3:2 or 4:3 being more common.

Exterior Walls, Columns, and Fire Walls
Columns require strength (material, thickness, and length and width dimensions) to support the building, but in multi-story distribution centers, walls also play a role in maintaining the building's strength (called structural walls). Therefore, walls cannot be modified after construction, such as by creating openings.
Tera settings are 200mm for exterior walls, and 700mm x 700mm columns per floor, increasing by 100mm for each additional floor, with a column pitch of 10m.
The building's projected area is calculated based on the center of the exterior wall thickness (100mm inward for a 200mm wall thickness).

Changes to Tera settings for exterior wall thickness, column span, and fire wall thickness are reflected in the area calculation.

Floor, Beam, and Elevation Dimensions
The first floor is 1000mm high, with floor heights of 7000mm above each floor. The floor thickness + beam height is calculated as 1000mm.

Multi-story Buildings and Eaves
Eaves are rain shelters installed at the entrances and exits of distribution centers. Buildings with three or more floors do not have eaves, and trucks often enter the building (referred to as a berth-integrated type in Tera calculations).

50% of the eaves area is added to the building's projected area, and the building coverage ratio is calculated as (building projected area + eaves area * 50% /) / site area.

Emergency Stairs/Elevators
For buildings with two or more floors, the area of ​​emergency stairs and elevators is added.
In Tera calculations, a fire wall is installed every 1,500 m2 of the total building area, and a 1.5m-wide emergency staircase (2.3 m2 x 2.3 m2 freight elevator area x 1.5 sets) is added every 1,500 m2.

Main Building/Separate PL Automated Warehouse
A distribution center is typically constructed in a single building rather than multiple buildings.
However, in rare cases, an automated warehouse is constructed as a rack building (a column-less building with a roof and wall covering attached to the shelving components) and a separate building is constructed. While rare, this impacts the site layout (especially aisle width), so we decided to incorporate it into Tera Calculation 2.
Automated warehouses increase the number of shelves to maximize investment efficiency, and this often results in an open-air structure on the second and third floors. A floorless (open-air) building structure is not structurally or cost-effective. When introducing an automated warehouse, it is worth considering whether to have it separate or integrated into the distribution center (main building).

Building Type 40 Pattern Calculation
There are 40 different building type 40 patterns: 2 separate building categories (separate building A and separate building B have the same area) * 5 floors * 2 with or without eaves * 2 berth surfaces. The area and main dimensions of these 40 patterns are calculated and displayed in a table (exportable to Excel). The site area screen obtains building information from this table.

Building Specifications and Multi-Level Center Calculation
You can change the number of floors, presence/absence of separate building, and other settings on the building area screen to see how the building's (main building) vertical and horizontal dimensions change, but this display is temporary and does not affect the site area calculation. (Building Type 40 Pattern Calculation is used for site area calculations.)
Main Building Plan Dimensions
The building area screen displays the building's (main building) dimensions, and you can change the vertical dimension to check the horizontal dimension. However, this display is temporary and does not affect the site area calculation.

Main Building Elevation Dimensions
Although not used for area calculations, the height dimensions are shown to give an idea of ​​the building.

Plan and Elevation Dimensions of the Separate PL Automated Warehouse
This shows a diagram and approximate dimensions of the PL Automated Warehouse (rack building) when a separate building is used.

Item 6. Total Logistics Space Area and Area Adjustments
The logistics space area is calculated separately for shipping space, receiving space, shipping work space, storage space, and office/welfare area. These areas can be shared during off-peak hours or by optimizing operational processes. The areas that can be shared to reduce logistics space area are receiving and case sorting.
Additionally, additional space must be added to the above calculation for materials and auxiliary material storage areas and main aisles.

Receiving Space Sharing
Typically, receiving volume is concentrated in the morning before shipment. If the morning's receiving volume is 60% and the shipping space can be used 100% as receiving space, the load on the receiving space will be reduced by 60%. Since other factors are involved in the area calculation, a simple 60% reduction is not possible, but the reduction is certain.
While this calculation is not incorporated into Tera settings, please consider it.

Case Sorting Sharing
Case sorting is a work operation that is expected to be performed consecutively with sorting from the storage space. Case shipments have a large volume of goods, leaving the shipping space empty before sorting. Parts of the main aisle are infrequently used. Parts of the storage space have infrequently used loading and unloading aisles. Work efficiency does not decrease even if sorting spaces are dispersed as long as they are on the path from the storage space to the shipping space. There are elements that can be shared between the sorting space and other spaces.
While this is not incorporated into the Tera settings, please consider it.

Materials and Auxiliary Material Area
This includes shipping cardboard boxes, their packaging tape, unused shipping labels, and various forms.
Because shipping cardboard accounts for a large proportion of storage, the volume of cardboard shipped (used for bulk shipments) determines the area. In Tera settings, if 1,000 PL of goods are stored in the storage space, this is calculated as 20 PL (storage space PL number * 2%).

Main Aisle Settings
If the receiving space and storage space are not adjacent, or if the storage space and shipping work space are not adjacent, a transport aisle is required.
The Tera settings calculate the distribution center's 4m x horizontal dimension, but as a guideline, consider 50% of the above calculation.

Logistics Space Calculation
The logistics space calculation, taking into account final adjustments to the logistics space and the main aisle, is used as the base value for setting the building specifications.

Section 3: Calculation of shipping work space area
Because case shipments and bulk shipments use different work methods, they have different work areas and calculation methods. Case shipments and bulk shipments are calculated separately to clearly define the shipping work space and improve calculation accuracy. Case shipments are removed from the warehouse on an item-by-item basis and sorted by destination. Bulk shipments are removed from the warehouse on an item-by-item basis and stored on flow or medium-weight storage shelves, from which they are picked according to their destination.
The shipping work space also includes space for inspection and packaging.
Tera Calculation 2 calculates that inspection of case shipments is performed during sorting, while inspection and packaging for bulk shipments are performed in a special inspection and packaging area. If inspection at the time of picking is selected, which is not adopted in Tera Calculation 2, an inspection area is not required, and the inspection and packaging area can be the space used for cardboard packaging for small-lot collection destinations and individual shipments that cannot be shipped in shipping containers.

Handling Items Not in Shipping Data
Inventory items not included in the shipping data (number of items not shipped) were entered on the inventory estimation screen. These items will be added to the bulk shipping item rank D calculation.
In Tera settings, the number of inventory items is calculated as 120% of the number of items in the shipping data, and the number of unshipped items = 918. Therefore, the bulk shelving calculation is performed as follows: Shipping Data Item Rank D = 2164 + 918 = 3082.
This calculation is reflected in the calculation of the number of items = shelf width. The first requirement for shelf calculations is that there must be enough storage width for the number of items.

The calculation procedure is to determine the number of shelf widths and shelf width volume (determined by the number of widths per shelf) and then check the shelf inventory days. To increase shelf inventory days, reduce the number of widths per shelf (increase the width volume); to decrease shelf inventory days, increase the number of widths per shelf (reduce the width volume). This determines the shelf specifications and number of shelves. The more openings per shelf there are, the fewer the number of shelves; the fewer, the more.
The guideline for inventory days is 3-5 days for flow shelves and 7-14 days for medium-weight shelves. If the inventory days are short, the number of shelves will be reduced (the installation area will be smaller), but shelves will be restocked more frequently, making operations more difficult.

Case shipments are sorted onto basket carts (shipping destination).
1. Determine the calculated values ​​for the three types of basket carts.
Cage Cart 1100w, 1100d, 1700h
Cage Cart Load Capacity = (1.1 * 1.1 * 1.4) * Cage Cart Loading Ratio
Cage Cart Footprint Area = 1.2 * 1.2
Cage Cart Aisle Area = 1.2 * 1.5

Cage Cart 1100w, 800d, 1700h
Cage Cart Load Capacity = (1.1 * 0.8 * 1.4) * Cage Cart Loading Ratio
Cage Cart Footprint Area = 1.2 * 0.9
Cage Cart Aisle Area = 1.2 * 1.2

Cage Cart 850w, 650d, 1700h
Cage Cart Load Capacity = (0.85 * 0.65 * 1.4) * Cage Cart Loading Ratio
Cage Cart Footprint Area = 0.95 * 0.75
Basket cart aisle area = 1.2 * 1.1
2. Based on the calculation in 1, calculate the number of basket carts per destination for each destination rank.
Calculate the volume/number of destinations by rank. If the value is 0.5 or higher, use 1 cart per destination; if it is 0.5 to 0.4, use 1 cart per destination; if it is 0.5 to 0.4, use 1 cart per destination; if it is 0.4 to 0.3, use 1 cart per destination; if it is 0.3 to 0.2, use 1 cart per destination; if it is 0.2 or lower, use 1 cart per destination; and if it is 0.2 or lower, use 1 cart per destination. Calculate the number of basket carts to set up for sorting based on the following calculation conditions.
3. Divide the calculation in 2 by 3 batches to calculate the sorting area per batch.
4. Multiply the calculated value in 3 by the area multiplier.

Bulk shipments are picked.
1. Specify flow shelving or medium-weight shelving by destination rank.

1-1. For bulk shipment rank A1, specify flow shelving and set the flow shelving specifications.
Shelf width = 2400, Shelf depth = 2050, Shelf height = 2114, Number of shelves = 4, Number of openings (per shelf) = 5
1-2. Calculating the floor area per flow shelf
Shelf area = Shelf width * Shelf depth / 1000^2
Pic aisle area per shelf = Shelf width * 800 / 1000^2
Replenishment aisle area per shelf = Shelf width * 800 / 1000^2
Calculated floor area per shelf = Shelf area + Pic aisle area per shelf + Replenishment aisle area per shelf
1-3. Calculating the volumetric opening per shelf for flow shelving
Effective shelf width A = Shelf width – 60
Effective shelf width = (Effective shelf width - (Number of openings per shelf) * 20 + 20) / Number of openings per shelf 20 is the number of openings + 1
Effective shelf depth = Shelf depth
Effective shelf height = (Shelf height - (80 * Number of shelves + 20)) / Number of shelves 80 is the material thickness, and 20 is the loss on the first shelf
Effective shelf volume = (Effective shelf width * Effective shelf depth * Effective shelf height) / 1000 ^ 3
Calculated shelf volume = Effective shelf volume * (Shelf_Opening volume filling rate / 100)
Calculated volume per shelf = Calculated shelf volume * Number of shelves * Number of openings per shelf
1-4. Tera settings specify flow shelving for A1 and A2 ranks.

2-1. For bulk shipment Rank B, specify medium-duty shelving and set the medium-duty shelving specifications.
2-2. Calculating the floor area per medium-duty shelf
Shelf area = Shelf width * Shelf depth / 1000^2
Pic aisle area per shelf = (Shelf width * 600) / 1000^2
Calculated floor area per shelf = Shelf area + Pic aisle area per shelf
2-3. 'Shelf Frontage Volume Calculation
Shelf Width Effective = Shelf Width – 60
Frontage Effective Width = Int((Shelf Width Effective - Number of Frontages per Shelf * 10) / Number of Frontages per Shelf + 0.5) 'Frontage: The gap of 10 is the number of frontages + 1.
Frontage Effective Depth = Shelf Depth
Frontage Effective Height = Int((Shelf Height - (130 + Number of Shelves * 40)) / Number of Shelves + 0.5) 'The first shelf is included in 130.
Frontage Effective Volume = (Frontage Effective Width * Frontage Effective Depth * Frontage Effective Height) / (1000 ^ 3)
Frontage Calculated Volume = Frontage Effective Volume * (Shelf_Frontage Volume Fill Rate / 100)
Calculated Volume per Shelf = Frontage Calculated Volume * Number of Shelves * Number of Frontages per Shelf
2-4. The Tera settings specify medium-weight shelves for B, C, and D ranks.

Int (*** + 0.5) means that the calculated value is rounded to the nearest 4.

The bulk shelf summary table displays the calculation process and results based on the above formula.

Inspection and Packaging for Bulk Shipments
All picked bulk shipments are placed in shipping containers and transported to the inspection and packing area.
(Products shipped in cases are inspected during case sorting.)
Inspection. The packing area is:
1. 8.252 bulk shipments per hour = 26,449 bulk shipments / 31% peak volume
2. 24,756 bulk shipment total processing time = 8.252 bulk shipments per hour / 3 seconds inspection time per bulk shipment
3. 7 inspection lines = 24,756 bulk shipment total processing time / 3,600 seconds 'To process within one hour'
6. Required area 45.4 = Number of inspection lines 7 * Area per line 6m2 * Area multiplier 110%
The 6m2 area per line varies depending on the size of the shipping container.

Shipping Space Area Multiplier
Since there are multiple tasks with different tasks, the shipping space area multiplier is set for each task.

Displaying Shipping Workspace Calculation Results
When calculating bulk shipments, we mentioned that the shelf specifications are determined by checking the shelf's inventory days. In this table, the "Inventory" flow shelves (3.5 days) and medium-volume shelves (12.8 days) represent the shelf days of interest.
This workspace inventory volume affects storage space inventory, as

Storage Space Inventory = Total Inventory - Workspace Inventory.

Section 2 Inventory Estimation
The method for calculating inventory amounts from shipping data was described in the previous section.
As a calculation example, we will explain the procedure for calculating inventory amounts (PL equivalent) from shipping data 2022/05/09.
1. Calculate shipping amounts for 2022/05/09 by item rank (sequential numbers 1-5).
2. Specify maximum inventory (days) and safety stock (days) (sequential numbers 7-8) and calculate stable operation inventory (days). The formula is stable operation inventory = (maximum inventory (days) - safety stock (days)) / 2 + safety stock (days) (sequential number 9).
3. Calculate stable operation inventory quantity. The formula is shipping amount * stable operation inventory (days).
4. Calculate stable operation inventory * shipping amount (sequential numbers 10-14). Sequential numbers 16-18 are calculated as stable operation inventory / number of items.
5. The key to this spreadsheet is calculating the pallet stowage method. Single loading is when one item is loaded per pallet, while double mixed loading is when two items are loaded per pallet. For mixed loading, the first number indicates the number of items loaded on the pallet.
To distinguish between single loading and mixed loading, if the inventory per item (PL conversion) is 0.5 PL or more, it is considered single loading, 0.5PL to 0.33 is a double mixed load, 0.32 to 0.25 is a triple mixed load, 0.24-0.125 is a triple mixed load, and 0.125 or less is a triple mixed load.
The PL conversion for mixed loading is calculated as the number of items divided by the number of PL loaded items.

In Tera calculations, the number of shipped items in row B, I_D rank for loose shipments is added to the number of unshipped items. Additionally, when calculating storage space, the amount is calculated as 1.1 times the above amount (Tera setting).

Chapter 7 Tera Calculation 2_Distribution Center Size Calculation

Section 4. Calculation of storage space area
Case shipment items are shipped directly from the storage space, so all inventory becomes storage space inventory. Bulk shipment items are replenished from the storage space to the shipping workspace and picked and shipped from the shipping workspace (flow or medium-volume shelves).
A certain amount of bulk shipment items is stored on these flow or medium-volume shelves. Therefore, the inventory of bulk shipment items in the storage space is the total inventory of bulk shipment items minus the shipping workspace inventory.

Storage Space and Shipping Workspace Quantity Allocation Calculation
The Storage Quantity Allocation tab page shows the calculation process for calculating the storage space quantity by subtracting the shipping workspace inventory from the total inventory.

The key point is that the calculation calculates the number of D-rank bulk shipment items that are stored only on the shipping workspace shelves and are not stored on the storage space shelves.
Total number of bulk D-rank items = 2847
Total volume of bulk D-rank items = 118
Bulk D-rank bulk shelf volume = 241
Bulk shelf volume ratio = 204%
Number of completed bulk shelf items 2847 = Int(Total number of bulk D-rank items * ((Bulk shelf volume ratio / 100) * 0.6) + 0.5)
Of the 3082 bulk shipped D-rank items (including unshipped inventory), 2847 are stored on shelves in the shipping workspace and not on storage space shelves. The number of bulk D-rank items stored on storage space shelves is 235.

Another point to note is that the shipping workspace shelf calculation uses volumetric conversion, while the storage space shelf uses product liability conversion. The number of pallets stored cannot be accurately calculated using volumetric conversion. This is why the product liability load number (loading module) of cases is set for each item in the shipping data item.

Shipping Rank and Storage Facility Allocation
The Shipping Rank and Storage Facility Allocation screen allows you to assign storage equipment to item ranks.
For each rank, five types of storage facilities can be assigned, including PL Fixed Shelving, PL Motorized Shelving 1, and Motorized Shelving 2, via a combo box. Pushback shelving and PL Automatic Warehouses are also available.

All facilities are subject to Fire Service Act regulations.
The bottom of the items stored on the top shelf must be 5,000 m2 or less. When this exceeds 5,000 m2, a virtual floor is added, meaning a 200 m2 facility has a virtual floor of 200 m2 (virtual floors are added in 5,000 m increments). While a typical building requires a fire wall every 1,500 m2, a building with an additional 200 m2 of virtual floor space requires a fire wall for every 1,300 m2 of floor space. A virtual floor is a calculated floor that is legally required even if no actual floor exists.

Fixed PL Shelving
All tera calculations use a pallet size of 1100mm wide, 1100mm deep, and 1350mm high (including a 150mm PL height).

Placing one item on a pallet is called single storage (single PL), while placing two items on a pallet is called mixed storage (double PL). Mixed storage is distinguished by adding the number of mixed items to the beginning of the name.
Items on a pallet are stacked vertically (called "bent stacking") to prevent mixing with other items. For this reason, mixed PL storage is less efficient than single items. Fixed PL shelving is the type of shelving used in most distribution centers. Because pallets are supported by beams, loading aisles can be created between shelves (called dual shelving), allowing for consistent loading and unloading of items on any pallet.
Unlike direct stacking, products are not placed on top of each other, preventing product damage, and because products are lined up in an orderly fashion on pallets, location management (a system that links products to shelf addresses for easy and accurate loading and unloading) is easy.
Shelves are anchored (floor-stopping brackets) 100-200 mm from the building (varies depending on height and proximity to the building) to prevent products and equipment from coming into contact with the building during loading and unloading, providing a distance (called clearance) to prevent contact between the building and shelves in the event of an earthquake.
The clearance between stored goods is measured by the shelf supports and cross beams. It is 100 mm for both pallet loads.

1. Using shelf installation section A and shelf auxiliary aisle B as the calculation units, the area required for section A to store 2 rows x 5 rows x 3 rows x 2 PL = 60 PL is 13.1 m x 5 m = 65.5 m2. When section B aisle addition is selected, 5 m x 2 m = 10 m2 is added to the calculation. However, since one shelf consists of 2 PLs x 3 levels, the calculation is an integer multiple of 6 PLs, so if there are 130 PLs, the calculation is 132 PLs.

For example, if 132 PLs need to be stored, 132 PLs / 6 PLs = 22 shelves are required. Since Section A has 10 shelves, the installation area required is 2.2 times the required area, or 65.5 m² x 2.2 = 67.7 m².

The required auxiliary shelf aisle is 2.2 times the required area, or 10 m² x 10 m² = 22 m².

PL Powered Shelving 1
PL powered carts are a commonly used piece of equipment.

PL powered shelving allows fixed PL shelves to be mounted on a powered cart. By moving the powered cart shelf, the loading aisle (2 aisles) is shared, reducing the aisle (to 1 aisle) and reducing the shelf installation area.

When powered shelving was first commercialized, it required track rails embedded in the floor, but rail-less systems have become more common. Railless electric shelving units do not require floor construction, which is one of the reasons for their widespread adoption.
The calculation method is the same as for PL fixed shelving units.
Note that because the electric trolley is 200-250 mm high, the height dimension of the PL shelf on the electric trolley is 200-250 mm higher than the PL fixed shelf. A control panel 400 mm high is installed on one side of the electric trolley in the connecting direction, making the PL fixed shelf dimension + 400 mm in the connecting direction.
Shelves with heavy loads move, causing concentrated shelf deflection, so attention must be paid to floor strength.

PL Electric Shelving Unit 2
PL Electric Shelving Unit 2 places two PL electric shelving units between PL fixed shelves, allowing loading and unloading in one aisle where three aisles would normally be required.

Pushback Shelving

[Teramoto Toshiyuki 4]

PL Automated Warehouse

Shipping Container Count Calculation

Pallet Module Calculation

Truck Trajectory Diagram

Forklift Handling Aisle Width

Area Ratio of Each Storage Facility [Teramoto Toshiyuki 5]

Section 4: Calculating required space

Item 1. Calculation of receiving space area and number of berths
When it comes to shipping, the distribution center cannot arbitrarily increase or decrease the ordered shipping quantity or change the delivery date and time. On the other hand, when placing an order, they can specify the quantity and arrival date and time for receiving goods. By controlling receiving, distribution centers avoid busy times and busy days of the week when receiving goods.

Receiving goods are received from the shipping space during non-shipping times.

Sharing this shipping space can reduce receiving space.

Although rare, there are also distribution centers where a receiving agent (an employee of another company) performs the receiving process, transports goods to storage shelves, and replenishes them on bulk picking shelves in the middle of the night when there are no shipments. Such distribution centers use shipping berths and shipping space for receiving goods, so receiving berths and receiving space are not required.

A large volume of incoming goods does not necessarily mean that the number of berths or receiving space will be large.

Tera Calculation 2 calculates the number of berths and receiving space from the amount of incoming goods, and then allows you to input the new amount of receiving space and shipping space that can be shared and recalculate the receiving berths and receiving space.

For some imported products, managing arrival dates and times can be difficult, resulting in staggered arrival dates. In such cases, measures such as providing evacuation and waiting space on and off the premises are necessary.

Below, we explain how to calculate arrival space and the meaning of terms.

Peak Arrival Volume
Peak arrival volume refers to the volume during the busiest hour of the day (1 hour). Arrival volume is the volume calculated on the Arrival Estimate screen. The ratio indicates what percentage of the peak arrival volume corresponds to a 100% estimated arrival volume. Ratio = (Peak Arrival Volume / Daily Arrival Volume) * 100.

Receiving Method
This is the pattern for when ordered products arrive at the distribution center. Tera Calculation 2 offers three patterns. Set the type of vehicle, loading method, and loading ratio for peak arrivals.

Volume Ratio
The ratio of volume allocated to Receiving Methods 1-3. Volume for Receiving Method 1 = (Total Arrival Volume for Receiving Method 1 / Arrival Volume) * 100.

Incoming Truck Vehicle Type
The loading capacity of the loading platform varies depending on the truck model. To set the loading capacity, select one vehicle model for the calculation. Keep in mind that the turning radius varies depending on the vehicle model selected, which will affect the site layout. Larger vehicles are used for inbound shipments than outbound shipments due to the larger quantity per item. Some vehicles also deliver to multiple distribution centers (and do not unload all of their cargo).
Containers are used for long-distance transportation, and 40-foot containers, in particular, are often used for imports.

Incoming Trucks and Loading Rate
Normally, a truck's loading rate = cargo volume / truck internal volume. However, the loading rate at the time of arrival is calculated as the loading rate of the inbound truck = unloaded cargo volume / truck internal volume. For example, if a 2-ton long truck receives goods with a 90% loading rate and unloads 20%, the loading rate of the inbound truck is considered to be 20%.

Truck Loading Method
There are two loading methods: pallet loading and direct case loading. While pallet loading is desirable for quick loading and unloading from trucks, vehicles with a load capacity of less than 4 tons have a low loading rate for pallet loading, so direct case loading is common. Pallet loading is achieved by large trucks that can load two pallets per truck bed width, but the truck bed height results in a loss of two pallet thicknesses (150 mm x 2 pallets).

Large long-distance trucks often use direct case loading to avoid this pallet thickness loss.

Direct case loading is calculated using case volume. Pallet loading is calculated as direct case loading calculation * ((number of loaded pallets * 150) / truck bed height).

Incorporating empty transport equipment into calculations

When loading pallets, the receiving berth area is the waiting area for shipping + the temporary storage area for returned empty pallets. When loading cases directly, the temporary storage area for returned empty pallets is calculated as 0.

Number of Receiving Berths
A receiving berth is a distribution center opening (also called a dock) required for unloading incoming trucks. The number of receiving berths is the number of docks required during peak hours (1 hour). It is calculated by dividing the cumulative truck arrival time (minutes) per hour by 60 minutes. Truck arrival time is preset for each vehicle type. (See Receiving Space Calculation.xlsx.)

Receiving Space Area Multiplier
The calculated receiving space area does not take into account gaps between waiting products, aisles for workers to load and unload, and office space. The calculated number of receiving berths does not take into account inspection time, document processing time, and delays caused by interference between incoming and outgoing trucks.
These required times are taken into account using the area multiplier.

Calculating distribution center size is not complicated; it's a series of additions and subtractions involving the repeated movement and storage of cases and bulk items. There's no advanced mathematics involved. However, the units change frequently. Receiving is measured in cases, storage in mixed pallets, picking and replenishing shelves in the shipping area in cases, and picking in bulk. The units change depending on the purpose of the calculation. Units used for the same item include the number of shipments (rows), bulk items, case conversion, product liability conversion, and volume conversion, with the less frequently used weight conversion. While the bulk items are the basis for calculations, it's important to always be able to find each conversion value.

While the products handled are solid objects, they are considered liquids like water for calculations, and calculations are based on the capacity and fill rate of the container (shelf opening capacity, truck bed capacity). Cases are measured by volume, but the reason we use volume conversion is because of the above-mentioned meaning.

While the bulk volume is calculated from the case volume, the bulk volume also includes the volume of packaging (cardboard). Ideally, the volume of packaging materials should be excluded, but it is calculated as is. Please understand that Tera Calculation 2 is a rough calculation.
Tera Calculation 2 uses software to connect individual calculations used on-site. There may be other calculation methods, but if there is an easier-to-calculate and more accurate method, please choose that. Tera Calculation 2 is simply an example for calculating distribution center size.
Tera Calculation has nearly 200 input fields, but all of them are entered in the Tera settings. Simply pressing the execute button will perform all calculations, up to the site size, and complete the calculation. Also, if you change the Tera settings, check all input values ​​again and recalculate.
Shipping data has item classification, shipping classification, and shipping route classification, but Tera Calculation 2 does not take these classifications into account. In particular, it calculates all cardboard shipments assuming that they are shipped in shipping containers. In the next improved version, we plan to include this classification in the calculations.

Section 8 Calculation of the size of logistics equipment not included in Tera calculation
Waste cardboard processing area, temporary storage area
Pallet container washing area
Management offices for each space
Toilets and washrooms
Verification of evacuation routes
Consideration for other departments occupying the space

Whether or not the company's documents and ledgers are legally required to be kept for a certain period of time

Legal considerations for the building's exterior walls, fire walls, and columns
Consideration for laws such as the Building Act and Fire Service Act (application may vary by location)
Road access within the building and site, security and crime prevention, parking and bicycle parking areas, green space height restrictions, and neighborhood coordination

Section 7 Building pay ratio/Floor area ratio
The building coverage ratio varies depending on the zoning (the area is divided into 13 regions according to use in order to form planned urban areas). There are some areas where construction is not possible, so please check other copyrighted works.
The calculation is: building coverage ratio = (building projected area + eaves area * 50%) / site area, floor area ratio = total floor area (virtual floor added) / site area. Tera settings use a building coverage ratio of 60% and a floor area ratio of 200%.

Section 6: Site Area Calculation
When incorporating a building into the site layout, it is necessary to ensure truck routes (truck turning corridors) as well as building coverage ratio and floor area ratio. Incoming berths are often used for large trucks, while outgoing berths are used for small trucks, but there tends to be a need for a larger number of berths. The minimum required truck route (effective width) is truck turning corridor + 1m.
In addition to truck routes, the site also has legally designated green spaces such as car and bicycle parking areas and truck waiting areas. Ensuring safe pedestrian routes that avoid interference with trucks is particularly important (large centers have a total of more than 500 people passing through).

Section 5: Office and Welfare Space Calculations
ここに文章を書きます。

Item 2: Calculation of shipping space area and number of berths
The shipping workspace is where items removed from the storage space by item are sorted for case shipments, and picked and organized by destination for loose shipments. Inspection and packaging are also included in this space.

The process order is storage space first, followed by workspace, and finally shipping space.

The order of consideration is reversed because shipping is the basis: shipping space calculation, shipping workspace, and then storage space.

Since the calculation assumes that all products are in storage at the time of shipment, receiving-related matters are not included in shipping considerations.

Peak Shipping Volume [Teramoto Toshiyuki 3]
Tera Calculation 2 analyzes shipping data in advance and displays the hourly volume ratio = (hourly volume / daily volume) * 100. Compare this volume ratio with each displayed table and enter the volume ratio.

To increase equipment utilization, we aim to keep the volume ratio below 25%.
If the ratio exceeds 30%, Tera 2, which is a rough scale calculation, can be set at 30%, but when detailed consideration is made, measures such as accelerating work should be taken to reduce the volume ratio, otherwise excessive equipment specifications will be configured.

Shipping Method and Total Volume Ratio
Three truck types for shipping can be calculated. The total volume ratio is the ratio allocated to each type when the daily shipping volume is set at 100%.

Shipping Truck Type and Loading Rate
There are 11 truck types (2T Standard, 2T Long, 2T Long Wide, 4T Wing Truck, 4T Aluminum Truck, 4T Aluminum Van, 4T Wing Truck, 10T Super, 14T G Cargo, 20ft Container, 40ft Container).

Taking into account the narrow unloading area at the destination and the need for on-road unloading, trucks smaller than the receiving trucks are selected; containers and vehicles over 10T are not selected. The loading rate for shipping containers and transportation equipment is lower than the receiving loading rate.

Shipping Loading Methods and Transportation Equipment
To reduce unloading time, transportation equipment such as basket carts is often used. Seven types of transportation equipment are available (direct loading, 1100*1100 pallet, 850*650 basket cart, 1100*800 basket cart, dolly cart, double-sided six-wheel cart, and double-sided cart). Cases are typically delivered using basket carts, while bulk containers are typically delivered using dolly carts or double-sided carts.

Bulk Shipping Containers
Dedicated services, which deliver regularly to large destinations, allow for the return of transportation equipment and containers. On the other hand, shared delivery and courier services are used for small-lot shipments and individual destinations. Shared delivery and courier services, which are joint deliveries with other companies, are one-way, and dedicated services do not allow the return of transportation equipment or containers.

In-house (dedicated) delivery services allow the use of transportation equipment and shipping containers, while shared delivery and courier services ship in cardboard packaging.
The process involves inspecting both items using shipping containers until picking is complete. Based on the shipping category (shipping container/cardboard box) in the shipping data, items in the shipping category (shipping container) are shipped as is, while items in the shipping category (cardboard box) are repackaged and shipped in a cardboard box.

Shipping containers are available in four sizes: 30, 40, 51, and 60. The number before the size indicates the capacity in liters.

Fill rate = product volume / container internal volume, with a maximum of 90% as a guideline, and around 70% for larger items or when cushioning material is required. Additionally, factors that lower the fill rate include shipping containers with small shipment volumes that do not reach the shipping container's capacity, and fractional shipping containers even when multiple shipments are made. A fractional shipping container is a shipping container filled with 0.5 containers when three shipping containers are being shipped and the product occupies 2.5 shipping containers. The term "fractional" also has the same meaning when used in terms such as fractional pallets and fractional carts.

Standard shipping containers are foldable, reducing their volume. The calculation assumes that empty shipping container storage space is folded five levels and loaded onto a dolly when returned. The storage space for a 40-type empty shipping container is calculated as 0.0118 m2 per container. A dolly is a dedicated container carrier.

Shipping Space Area Multiplier
The shipping space area calculation does not take into account gaps between containers, work flow, or loading and unloading within the shipping space. This multiplier calculates the actual area, taking into account the required space. A guideline is 120% to 130%.

Explanation of the Tables on the Tab Pages
The Calculation Results tab page displays the shipping space calculation process and results in a table.
Other tab pages include Shipping Truck Specifications, Transportation Equipment Specifications, Transportation Equipment Load Capacity by Truck, Bulk Container Load Capacity by Transportation Equipment, and Number of PL 2-Level Bulk Containers by Truck. The calculation results are also displayed in a table. The calculation results are also displayed.

Section 3 Estimation of incoming quantities
You can estimate incoming quantities using Tera calculations.

Section 1: Incoming Quantity Estimation
Inventory fluctuates between maximum inventory and safety stock. Fluctuating inventory = maximum inventory - safety stock
If the fluctuating inventory days = 6, incoming items arrive every 6 days, reaching maximum inventory on the arrival date, and fluctuating inventory will be 0 immediately before the next arrival date is confirmed.

As explained in the previous section, spreading out arrival dates reduces inventory levels across the entire distribution center (total inventory of all items). Let's explain this with a calculation example.

1. Sequence numbers 1-5 represent shipping quantities.

2. Sequence numbers 6-7 set maximum inventory and safety stock, and calculate maximum inventory - safety stock = incoming cycle. (Sequence number 8)

3. The number of incoming items is the number of items (Sequence number 1) / incoming cycle (Sequence number 8)

4. Since incoming quantities are shipping quantities = incoming quantities, the values ​​for Sequence numbers 2-5 and 10-13 are the same.

5. The incoming quantity per item table is used to determine the incoming packaging style.
If the receiving quantity per item is 0.5 PL or more, it is received in pallet units. 0.5 PL or less receives in case units, and 0.5 cases or less receives in bulk units.
B-row I_C and B-row I_D (sequence number 16), which are products shipped in bulk, receive in case units.
7. Calculate the total receiving quantity by adding up the products shipped in cases and the products shipped in bulk.

Note: The number of items, 1,380, in B-row I_D (sequence number 1, products shipped in bulk) is calculated as the number of shipped items, 480, plus the unshipped inventory, 900.

Section 1: Difference between average inventory and stable operating inventory
The image on the left shows the inventory estimation screen flow for Tera Calc 2.

Inventory refers to products that are received and stored in advance for shipment, and inventory quantity refers to the amount of inventory.
Inventory quantity can also be expressed in units of inventory days, which means the amount of inventory equivalent to the number of days of shipping. In Tera Calc, inventory (days) refers to inventory days.
Maximum inventory is the upper limit of inventory; no more inventory is held than this.
Safety stock is the lower limit of inventory that is always maintained. In the event of delays in arrival or larger-than-expected shipments, items are shipped from this safety stock.
The fluctuating inventory is calculated by subtracting safety stock from maximum inventory, and daily inventory fluctuations fluctuate within this range.
The order point is the inventory on the order date, calculated by working backwards from the time an order is placed until the product arrives. The inventory at this order point is called the minimum inventory. Purchasing staff will place an order when inventory decreases to the minimum.
To maintain maximum inventory days and reduce storage volume, stagger the arrival dates of each item (if there are 180 items with 6 days' worth of fluctuating inventory, 30 items will arrive per day). By managing stable operation inventory = fluctuating inventory/2 + safety stock, the overall inventory level at the distribution center can be kept minimal and consistent. In Tera Calculation, this managed inventory is called stable operation inventory.

Let's explain with an example calculation. In the diagram below, if the shipment volume is 10 units per day, "Maximum inventory = Number of shipments * Maximum inventory period = 10 * 8 = 80 units."
"Average inventory = Maximum inventory/2 = 40 units." "Safety stock = Number of shipments * Safety stock period = 10 * 2 = 20 units." If the arrival period is 2 days, then "Minimum inventory = Safety stock + (shipment volume * arrival period) = 20 + (10 * 2) = 40 units."

Tera Calculation's inventory calculations do not use average inventory, but instead use the stable operation inventory calculation below.
"Fluctuating inventory = shipment quantity * (maximum inventory period - safety inventory period) = 10 * (8 - 2) = 60 units"
"Stable operation inventory = (fluctuating inventory / 2) + safety inventory = 30 + 20 = 50 units"

Based on the above calculation, if purchase orders are placed repeatedly at minimum inventory levels, maximum inventory = minimum inventory. If purchase orders are placed daily starting three days before shipment, maximum inventory equals "safety inventory + shipment quantity * 1 day." Some distribution centers, such as those selling milk with a short shelf life, have no safety inventory and simply ship same-day deliveries of goods received that day.

However, most distribution centers have inventory (maximum inventory) that is more than twice the minimum inventory.

Maximum inventory is set taking into account company-wide benefits, such as differences in purchase price depending on the quantity purchased, product availability, and, in the case of manufacturers, securing production lots.

Tera calculations are designed to allow for flexible adjustments to maximum inventory and safe-to-ship inventory, since setting inventory levels that can guarantee shipment volume solely for the distribution center's convenience results in low inventory levels that do not match the current situation.

Note: "Stable operation inventory" is a term used to explain Tera calculations and is not an inventory term. Also, "average inventory" has a different meaning from the inventory term "average inventory." Please refer to other books for the inventory term "average inventory."

Section 2 Estimation of Inventory Quantity
Some people say that there is no point in using Tera calculations to calculate inventory and receipt data when actual inventory and receipt data is already available.
However, the author believes that inventory and receipt data should not be used as is.
Whether the inventory and receipt data that record actual results are appropriate in relation to the shipping data can only be determined by comparing them with the inventory and receipt amounts calculated from the shipping data.
Tera calculations calculate inventory and receipt amounts from the shipping data.

The author believes that the author must explain to the data provider "where the inventory and receipt data compare in relation to shipments," and calculate receipt and inventory amounts based on a shared understanding with the data provider.
Neglecting this task can lead to overlooking potential problems and sometimes resulting in designing the system with incorrect settings.

Section 1 Data processing for scale calculation
Tera Calculation 2 uses PL conversion as its rank setting key. This is because it focuses on pallet storage in storage spaces that account for a large proportion of the distribution center's floor space.
While the source data is obtained from "T200," the calculation data uses the average of all shipments (Tera settings).
There are two reasons for this. 1. If a specific shipping date is used, items that were not shipped on that shipping date will be excluded from the calculation. 2. If a shipping date with a high number of shipments is used, the distribution center size will be larger than necessary; shipping dates with more shipments than average can be compensated for with safety stock.
The Tera settings use the average of all data, but calculations can also be performed for specific shipping dates, so please change the Tera settings to verify the difference in scale.
As mentioned in other chapters, case shipments and loose shipments are distinguished and calculated separately.
The calculations are stored in 32 tables in Access, including the data below.
This data includes loose quantities and case, PL, volume, and weight conversions. These tables are published so that you can use this Access data to try calculations other than Tera calculations.