T3_2_Inbound Space.vb - Detailed Specification

1. Overview

🎯 Module Purpose

T3_2_Inbound Space.vb is an advanced module designed to compute the requisite staging and dock area for inbound logistics operations. It leverages scientific calculations factoring in cargo volume, truck models, loading styles, and unloading dwell times.

1.1 Key Characteristics

📊 Diverse Data Inputs

Imports raw inbound volume metrics via Excel files, segmenting data by case-level and piece-level workflows.

🚛 Truck Profiling

Configures multiple truck capacities and accounts for both palletized and floor-loaded cargo profiles.

⏱️ Time-Based Sizing

Determines space requirements based on precise unloading cycle times and daily peak volume concentration ratios.

📐 Footprint Optimization

Calculates comprehensive square footage including truck staging queues and empty pallet return buffers.

1.2 File Information

Item	Details
File Name	T3_2_Inbound Space.vb
Line Count	962 Lines
Class Name	T3_2InboundFrom
Inheritance	System.Windows.Forms.Form
Libraries Used	System.IO, OfficeOpenXml (EPPlus)

1.3 Associated Files

Inventory_Inbound_Volume.xlsx: Base volume data split by case/piece output.
Inbound_Space_Calc.xlsx: Master data for truck specs and default unload times.
TeraCalcData Directory: System root directory for DB and Excel storage.

2. Architecture & Design

2.1 Class Structure

📦 T3_2InboundFrom Class

Base Class: System.Windows.Forms.Form

Access Modifier: Public

Primary Role: Provides the GUI and mathematical logic for inbound sizing.

2.2 Code Regions

Region Name	Line Range	Core Function
Inbound Volume Dgv Display	23-163	Reads and displays Excel volume data
Inbound Space Calc	165-578	Main mathematical sizing engine
PL/Case Volume Calc	580-637	Reverse-engineers case metrics
Unloading Time Update	639-858	Reads and refreshes dwell times
Unloading Time Save	860-940	Commits user customizations to Excel

2.3 Data Flow

Processing Pipeline

1. Excel Import
   ├─ Inventory_Inbound_Volume.xlsx (Raw Volumes)
   └─ Inbound_Space_Calc.xlsx (Truck & Dwell Specs)

2. Volume Aggregation
   ├─ Inbound generated from full-case picking
   ├─ Inbound generated from loose-piece picking
   └─ Total combined inbound cubic volume

3. Scenario Configuration (Up to 3 Truck Types)
   ├─ Assign vehicle specs (Type 1, 2, 3)
   ├─ Assign loading type (Palletized / Floor-loaded)
   └─ Assign workload distribution ratios

4. Bay Count Calculation
   ├─ Trucks per Day = Total Volume / Truck Capacity
   ├─ Total Dwell Time = Trucks * Unload Mins/Truck
   ├─ Apply Peak Hour Ratio
   └─ Result = Required Dock Bay Count

5. Final Space Sizing
   ├─ Staging Area = Bay Count * Truck Area * Clearance
   ├─ Empty Pallet Buffer Area
   └─ Total Required Footprint = (Staging + Buffers) * Safety Margin

3. Core Features

3.1 Data Import

📥 Inventory Inbound XLSX Loader

在庫入荷量XLSX読込(MySheet, Mydgv)

Function: Parses raw Excel data directly into the DataGridView.

Technology: EPPlus (OfficeOpenXml).

Target Sheets:

Case Shipping Volume
Piece Shipping Volume

Private Sub 在庫入荷量XLSX読込(MySheet As String, Mydgv As DataGridView) MyExcel = Dat保存Path & "\在庫入荷量.xlsx"

	Dim fi As IO.FileInfo = New IO.FileInfo(MyExcel)
	If fi.Exists = False Then
		MessageBox.Show("File not found")
		Return
	End If

	Using pkg As New ExcelPackage(fi)
		Dim sheet1 As ExcelWorksheet = pkg.Workbook.Worksheets(MySheet)
		' Data import logic...
	End Using
End Sub

3.2 Sizing Calculation

🧮 Inbound Space Calc 1()

Main Sizing Function

Execution Sequence:

Load Truck Specs into DGV()
Calculate Bays and Space 1()

📊 Bay & Space Mathematics()

Micro-Steps

Applies mathematical distribution across 3 parallel inbound configurations.

Step 1: Segmented Volume

Volume (m³) = Total Inbound Volume × Segment Ratio / 100

Step 2: Effective Capacity

Capacity/Truck = Nominal Truck Volume × Load Factor / 100

Step 3: Daily Truck Arrivals

Arrivals/Day = Segment Volume (m³) / Capacity per Truck

Step 4: Total Dock Dwell

Total Dwell Time = Arrivals/Day × Dwell Time/Truck (mins)

Step 5: Peak Hour Workload

Peak Dwell Time = Total Dwell Time × Peak Hour Ratio / 100

Step 6: Required Bays

Dock Bays = Peak Dwell Time / 60

Step 7: Staging Area Footprint

Staging Area = Truck Footprint × Dock Bays × Aisle Coefficient (1.5)

Step 8: Empty Pallet Buffer Area

Empty PL Area = (PL Footprint × Max PL per Truck × Dock Bays) / Empty PL Stacking Tiers (5)

Step 9: Grand Total Space

Total Inbound Space = (Staging Area + Empty PL Area) × Safety Factor

3.3 Helper Functions

Palletized Payload Volume()

Calculates effective truck volume when using pallets.

Volume = Pallet Count × Volume per Pallet

Floor-Loaded Payload Volume()

Fetches theoretical max volume directly from truck master data.

Dwell Time()

Fetches cumulative unloading time based on vehicle type and loading method.

Staging Area()

Calculates immediate buffer footprint behind the dock doors.

Area = Truck Footprint × Bays × 1.5

Empty PL Buffer()

Calculates holding footprint for retrieved empty pallets.

Area = (1.1 × 1.1 × PL Count × Bays) / 5 Tiers

3.4 PL/Case Reverse Engineering

📦 PL/Case Volume Calculator()

Functional Overview

Advanced heuristics to reverse-engineer average carton dimensions if raw data lacks them.

Logic Flow:

Derive average case volume from total aggregate metrics.
Iteratively scale a 4:3:2 W:D:H aspect ratio until the target volume is matched.
Assign resulting dimensions to pallet configurations.

' Reverse engineer dimensions via 4:3:2 ratio constraint
Dim V As Single = AverageCaseVolume * 1000 ^ 3 ' m³ to mm³
For i = 1 To 1000
	AvgCaseWidth = 4 * i
	AvgCaseDepth = 3 * i
	AvgCaseHeight = 2 * i
	If (AvgCaseWidth * AvgCaseDepth * AvgCaseHeight) >= V Then
		Exit For
	End If
Next

4. Data Metrics & Constraints

4.1 Volume Sourcing

Item	Formula	Description
Case Volume Base	Aggregated from Case Shipments	Inbound replenishment to support full-case picking.
Piece Volume Base	Aggregated from Piece Shipments	Inbound replenishment to support loose-piece picking.
Total Inbound Volume	Case Base + Piece Base	Gross daily replenishment demand in cubic meters.
Peak Target Volume	Total Inbound Volume × Peak Ratio / 100	Spike volume used for actual dock design.

4.2 Truck & Dock Design Parameters

⚠️ Critical Sizing Variables

3 Scenarios: Users can distribute freight across up to 3 distinct truck types to mirror reality.
Volume Ratios: The split percentage must equal exactly 100%.
Load Factor: Real-world trailer utilization (rarely 100%).
Peak Hour Ratio: Protects against morning/afternoon arrival clustering.
Aisle Clearance: 1.5x multiplier ensures MHE maneuvering space behind the trailer.
Safety Margin: Final multiplier applied to absolute area totals.

4.3 Unload Time Dwell Components

Task Component	Duration (Mins)	Description
Docking Approach	Variable	Time required to safely back into the bay.
Clerical Processing	Variable	Manifest review and WMS check-in.
Physical Unload	Variable	Core labor time executing the physical strip.
Audit & Inspection	Variable	Quality/quantity checks on the dock floor.
Undocking	Variable	Pull-away and exit time.
Total Dwell	Sum	The full cycle time the dock bay is occupied.

4.4 Sample Equation Flow

📝 Step-by-Step Resolution

Baseline Scenario:

Total Volume: 100 m³
Scenario 1 (Palletized): 60% share
Truck Class: 4-Ton Truck
Truck Capacity: 30 m³
Load Factor: 80%
Total Dwell Time: 60 mins/truck
Peak Hour Ratio: 30%

Calculation Sequence:

1. Target Volume = 100 m³ × 60% = 60 m³

2. Payload/Truck = 30 m³ × 80% = 24 m³

3. Truck Arrivals = 60 m³ / 24 m³ = 2.5 Trucks

4. Total Dock Dwell = 2.5 Trucks × 60 mins = 150 mins

5. Peak Workload Dwell = 150 mins × 30% = 45 mins

6. Required Bays = 45 mins / 60 mins = 0.75 → Rounds to 1 Bay

7. Staging Area = 15m² (Truck Footprint) × 1 Bay × 1.5 = 22.5 m²

8. Empty PL Area = (1.21 m² × 10 PLs × 1) / 5 Tiers = 2.42 m²

9. Final Inbound Space = (22.5 + 2.42) × 1.2 Margin = 29.9 m²

5. Data Architecture

5.1 External Excel Dependencies

📄 Inventory_Inbound_Volume.xlsx

Worksheet Name	Contents	Size
Case Shipping Volume	Replenishment demands for full-case workflows.	7 cols × 60 rows
Piece Shipping Volume	Replenishment demands for loose-piece workflows.	7 cols × 60 rows

📄 Inbound_Space_Calc.xlsx

Worksheet Name	Contents	Size
Tera Setting Dwell	System default unload cycle times.	20 cols × 23 rows
User Setting Dwell	Customized dwell times modified by user.	20 cols × 23 rows
Truck Specs	Dimension and volume master data by vehicle class.	15 cols × 12 rows

5.2 DataGridView Map

Control Name	Purpose	Data Source
Case Inbound Volume Dgv	Renders case volumes.	Excel: Case Shipping Volume
Piece Inbound Volume Dgv	Renders piece volumes.	Excel: Piece Shipping Volume
Aggregated Inbound Dgv	Renders unified view.	Combined via code
Truck Specs Dgv	Renders reference specs.	Excel: User Setting Dwell
Tera Dwell Setting Dgv	Renders system defaults.	Excel: Tera Setting Dwell
User Dwell Setting Dgv	Editable dwell grid.	Excel: User Setting Dwell
Calculation Results Dgv	Renders final answers.	Memory outputs

5.3 Application State Variables

' Inherited Global Variables (from T3_UtilitySoft.vb)
Public Dat保存Path As String     ' Storage root directory
Public MyExcel As String          ' Active Excel path
Public MySheet As String          ' Active Worksheet
Public MyDgv As DataGridView   ' Active target DGV

' Internal State Variables
Private Dgv表示_チェック As Integer  ' Initialization semaphore
Private 平均ケース幅 As Single         ' Avg Case Width
Private 平均ケース奥行 As Single       ' Avg Case Depth
Private 平均ケース高 As Single         ' Avg Case Height

6. Methods Reference

6.1 Initialization

スペース計算1入荷From_Load

Event Hook: Form Load

Execution Order:

Set init semaphore to 0.
Execute master file/path verification.
Render copyright and license expiry tags.
Load Excel volume data for Cases and Pieces.
Set init semaphore to 1.
Display aggregated volume grids.
Load Dwell Time tables.
Update text field UI.
Execute Pallet/Case heuristic scaling.

6.2 Display Renders

入荷量Dgv表示()

Function: Refreshes the aggregate volume summary UI.

Toggles:

Volume Mode Rb = True: Displays in m³ format.
Volume Mode Rb = False: Displays physical unit counts.

入荷トラック仕様Dgv表示()

Function: Renders read-only reference data for vehicles.

UI Rules:

Hides row and column headers.
Enforces ReadOnly state.
Applies N0, N1, N2 numeric formatting bounds.
Auto-sizes columns via AutoSizeColumnsMode.
Freezes critical reference axes.

6.3 Execution & Saving

入荷スペース計算開始Bt_Click

Function: Primary execution trigger.

Logic: Executes the main math module and highlights the results container.

テキスト集計Bt_Click

Function: Sub-totals the 5 micro-dwell parameters into a unified "Total Unloading Time" value before saving.

荷降ろし時間ユーザ設定_修正保存Bt_Click

Function: Commits UI edits back to the underlying Excel master file.

荷降ろし時間Tera設定Rb_CheckedChanged

Function: Factory reset. Overwrites all user-customized dwell times with the Tera System defaults after prompting for confirmation via MessageBox.

7. Usage & Workflow

7.1 Standard User Journey

📋 Step-by-Step Guide

Launch Screen
- Open Inbound Space from the main utility menu.
- Wait for Excel data to auto-populate the grids.
Verify Volumes
- Review the aggregate volume grid.
- Toggle between cubic meter volume and raw counts.
Tune Operational Parameters
- Set the Peak Ratio (e.g., 30% concentration).
- Set desired Pallet Load Factor (e.g., 75%).
- Set the Safety Margin Area Multiplier (e.g., 120%).
Configure Truck Arrivals (Up to 3 Profiles)
- Select vehicle classifications.
- Select loading style (Palletized vs Floor-loaded).
- Assign distribution percentages (must sum to 100%).
- Define the actual cubic utilization percentage for the trailers.
Execute
- Click the large calculate button.
- Observe the results grid populate.
Evaluate Outcomes
- Determine total required receiving docks.
- Determine total required inbound square meterage.
- Use these values for subsequent architectural layouts.

7.2 Modifying Dwell Times

🔧 Customization Process

Select the "User Setting" radio button to unlock edits.
Select the target vehicle class.
Select the target loading style.
Override the time values for approach, clerical check, physical unload, inspection, and exit.
Click the Sub-Total button.
Click Save to commit to the Excel master.

📌 Note: Saved settings persist across application restarts.

7.3 Factory Reset

⚠️ Restoring Tera Defaults

To purge custom dwell times:

Select the "Tera Setting" radio button.
A confirmation prompt will appear.
Clicking "Yes" will permanently overwrite the User sheet with the Tera Master sheet values.

⚠️ Warning: This operation is destructive and cannot be undone.

7.4 Troubleshooting

❌ Common Errors & Fixes

1. "File Not Found" Exception

Cause: Missing Excel files.
Fix: Ensure the `Tera計算Data` folder exists on a valid root drive (A: through F:).

2. #DIV/0! Error in Results

Cause: Attempting to divide by a zero payload capacity.
Fix: Ensure Truck Volumes and Load Factors are greater than zero.

3. Unreasonably High/Low Dock Requirements

Cause: Anomalous Peak Factor or Dwell Time inputs.
Fix: Verify Peak ratios (30-50% is standard) and Load factors (70-85%).

4. Allocation Total Mismatch

Cause: The 3 arrival profile distributions do not equal exactly 100%.
Fix: Adjust the percentage sliders/inputs until they balance.

8. Summary & Recommendations

🎓 Value Proposition of T3_2_Inbound Space.vb

Science-Based Sizing: Eliminates guesswork by deriving footprint directly from logistics physics.
High Granularity: Models realistic mixed-fleet arrivals across 3 distinct vehicle profiles simultaneously.
Excel Portability: Interacts seamlessly with Excel for transparent, auditable data persistence via EPPlus.
Adaptable: Allows seasoned engineers to override default dwell assumptions with real-world time-study data.

8.1 Usage Patterns

Pattern 1: Greenfield Design

Determine exactly how many dock doors and how much staging depth to include in architectural blueprints.

Pattern 2: Facility Audit

Compare theoretical minimum space against a currently congested facility to justify expansion.

Pattern 3: Throughput Stress Test

Scale up the volume inputs to see when existing dock doors will become a hard bottleneck.

Pattern 4: Process Optimization

Simulate shifting from floor-loading to 100% palletized receiving to evaluate the reduction in dock dwell times and required bays.

8.2 Notes for Maintainers

💡 Developer Guidelines

Hardcoded Excel Maps: Column and row offsets are hardcoded. If the template Excel file structure changes, the loop indices in the code must be updated.
EPPlus Compatibility: Validate EPPlus library versions. Upgrading beyond version 4.x introduces commercial licensing constraints.
Semaphore Integrity: Ensure the `Dgv表示_チェック` flag is properly handled to prevent race conditions during UI repaints.
Input Sanitization: While basic bounds checking exists, ensure user text inputs are safely cast to Doubles before execution.

📦 TeraCalc2 Manual