Assembly Workflow - End-to-End Process

Overview

The Assembly Workflow is a complete end-to-end business process for manufacturing finished goods from component items using a Bill of Materials (BOM). This process involves component explosion, availability checking, component consumption, and finished goods production with complete audit trail.

Business Context

Manufacturing Scenario:

A company manufactures widgets. Each widget requires:

1 Steel Frame

1 Motor

8 Bolts (M10)

0.5 Liters of Paint

1 Packaging Box

The production manager needs to:

Verify all components are available

Assemble 100 widgets

Track component consumption

Record finished goods production

Maintain complete audit trail

Process Participants

Production Manager: Initiates assembly
System: Validates availability, creates transactions
BOM: Defines component requirements
Inventory: Tracks component consumption and production
Audit Trail: Records all operations

Complete Workflow

Phase 1: Preparation

Phase 2: Availability Check

Phase 3: Assembly Execution

Detailed Steps

Step 1: Load BOM and Calculate Requirements

Purpose: Understand what components are needed

GET /api/boms/{bomId}

Response:

{
  "id": "bom-widget-001",
  "name": "Standard Widget Assembly",
  "parentItemId": "widget-001-id",
  "lines": [
    {
      "componentItemId": "steel-frame-id",
      "componentItemName": "Steel Frame",
      "quantity": 1.0,
      "unitSymbol": "EA"
    },
    {
      "componentItemId": "motor-id",
      "componentItemName": "Motor",
      "quantity": 1.0,
      "unitSymbol": "EA"
    },
    {
      "componentItemId": "bolt-m10-id",
      "componentItemName": "Bolt M10",
      "quantity": 8.0,
      "unitSymbol": "EA"
    },
    {
      "componentItemId": "paint-id",
      "componentItemName": "Paint - Blue",
      "quantity": 0.5,
      "unitSymbol": "L"
    },
    {
      "componentItemId": "packaging-id",
      "componentItemName": "Packaging Box",
      "quantity": 1.0,
      "unitSymbol": "EA"
    }
  ]
}

Calculation (for 100 units):

Steel Frame:  1.0  × 100 = 100 EA
Motor:        1.0  × 100 = 100 EA
Bolt M10:     8.0  × 100 = 800 EA
Paint:        0.5  × 100 = 50 L
Packaging:    1.0  × 100 = 100 EA

Step 2: Check Component Availability

Purpose: Verify sufficient inventory exists

GET /api/inventory/available?itemId={steel-frame-id}&locationId={production-location-id}

For each component:

{
  "itemId": "steel-frame-id",
  "itemNumber": "RM-STEEL-001",
  "itemName": "Steel Frame",
  "locationId": "production-location-id",
  "locationName": "Production Floor",
  "availableQuantity": 150.0,
  "unitSymbol": "EA",
  "unitName": "Each"
}

Availability Check:

Component         Required    Available    Status
Steel Frame       100 EA      150 EA       ✓ OK (50 spare)
Motor             100 EA      95 EA        ✗ SHORT (5 needed)
Bolt M10          800 EA      1000 EA      ✓ OK (200 spare)
Paint             50 L        60 L         ✓ OK (10 spare)
Packaging         100 EA      100 EA       ✓ OK (exact)

Result: Cannot proceed - Motor shortage of 5 units

Step 3a: Handle Shortage (if any)

Options:

Reduce production quantity: Assemble only 95 units (matches motor availability)
Wait for components: Delay assembly until motors arrive
Partial assembly: Assemble 95 now, 5 later
Substitute: Use alternate motor (if BOM allows)

Decision: Reduce production to 95 units

Step 3b: Execute Assembly

Purpose: Create assembly transaction and update inventory

POST /api/assembly/assemble
Content-Type: application/json

Request:

{
  "bomId": "bom-widget-001",
  "producedItemId": "widget-001-id",
  "producedQuantity": 95.0,
  "producedUnitOfMeasureId": "unit-each-id",
  "assemblyLocationId": "production-location-id",
  "transactionDate": "2025-01-24T10:00:00Z",
  "reason": "Production run #2025-001 - Standard widget manufacturing"
}

System Processing:

Validate BOM: Verify BOM exists and is active
Explode Components: Calculate actual requirements (95 units)
Create Transaction: Assembly transaction with details
Add Component Lines: One line per component (consumption)
Add Production Line: One line for finished goods (production)
Commit Transaction: Save to database
Dispatch Events: Trigger inventory updates
Update Inventory: Consume components, produce finished goods

Step 4: Inventory Updates

Component Consumption (decreases):

Steel Frame:  -95 EA  (150 → 55)
Motor:        -95 EA  (95 → 0)
Bolt M10:     -760 EA (1000 → 240)
Paint:        -47.5 L (60 → 12.5)
Packaging:    -95 EA  (100 → 5)

Finished Goods Production (increases):

Widget:       +95 EA  (0 → 95)

Step 5: Audit Trail

Transaction Record Created:

{
  "id": "transaction-20250124-001",
  "transactionType": "Assembly",
  "transactionDate": "2025-01-24T10:00:00Z",
  "reason": "Production run #2025-001",
  "assemblyDetails": {
    "bomId": "bom-widget-001",
    "bomName": "Standard Widget Assembly",
    "producedItemId": "widget-001-id",
    "producedItemNumber": "WIDGET-001",
    "producedQuantity": 95.0,
    "assemblyLocationId": "production-location-id"
  },
  "lines": [
    {
      "itemId": "steel-frame-id",
      "quantity": -95.0,
      "unitSymbol": "EA",
      "direction": "Consumed"
    },
    {
      "itemId": "motor-id",
      "quantity": -95.0,
      "unitSymbol": "EA",
      "direction": "Consumed"
    },
    {
      "itemId": "bolt-m10-id",
      "quantity": -760.0,
      "unitSymbol": "EA",
      "direction": "Consumed"
    },
    {
      "itemId": "paint-id",
      "quantity": -47.5,
      "unitSymbol": "L",
      "direction": "Consumed"
    },
    {
      "itemId": "packaging-id",
      "quantity": -95.0,
      "unitSymbol": "EA",
      "direction": "Consumed"
    },
    {
      "itemId": "widget-001-id",
      "quantity": 95.0,
      "unitSymbol": "EA",
      "direction": "Produced"
    }
  ],
  "createdBy": "production.manager@company.com",
  "createdDate": "2025-01-24T10:00:00Z"
}

Business Validations

Pre-Assembly Validations

BOM Exists: Parent item must have active BOM
BOM Active: BOM cannot be archived
Quantity Positive: Production quantity must be > 0
Location Operational: Assembly location must be operational
Components Stockable: All components must be stockable items
Components Active: All components must be active

Assembly-Time Validations

Component Availability: Sufficient inventory for all components
Negative Stock Check: If not allowed, prevent negative inventory
Location Tracking: If required, ensure location specified
Unit Compatibility: Component units match item unit class

Error Scenarios

Scenario 1: Insufficient Components

Problem: Not enough motor inventory (need 100, have 95)

System Response:

{
  "error": "Insufficient inventory",
  "details": [
    {
      "componentId": "motor-id",
      "componentName": "Motor",
      "required": 100.0,
      "available": 95.0,
      "shortage": 5.0,
      "unitSymbol": "EA"
    }
  ],
  "suggestions": [
    "Reduce production quantity to 95 units",
    "Wait for motor delivery",
    "Transfer motors from another location"
  ]
}

Scenario 2: BOM Not Found

Problem: Parent item doesn't have BOM defined

System Response:

{
  "error": "BOM not found",
  "message": "No Bill of Materials found for item 'WIDGET-001'",
  "action": "Create BOM before attempting assembly"
}

Scenario 3: Archived BOM

Problem: BOM was archived

System Response:

{
  "error": "BOM inactive",
  "message": "BOM 'Standard Widget Assembly' is archived and cannot be used",
  "action": "Unarchive BOM or create new BOM"
}

User Interface Considerations

Assembly Screen Layout

┌─────────────────────────────────────────────────────────┐
│ Assembly: Premium Widget                                │
├─────────────────────────────────────────────────────────┤
│ Production Quantity: [100] EA                           │
│ Assembly Location:   [Production Floor ▼]              │
│ Reason:             [Production run #2025-001]         │
├─────────────────────────────────────────────────────────┤
│ Component Requirements:                                 │
│                                                         │
│ Component         Required  Available  Status          │
│ ───────────────────────────────────────────────────    │
│ Steel Frame       100 EA    150 EA     ✓ OK           │
│ Motor             100 EA    95 EA      ✗ SHORT (-5)   │
│ Bolt M10          800 EA    1000 EA    ✓ OK           │
│ Paint             50 L      60 L       ✓ OK           │
│ Packaging         100 EA    100 EA     ✓ OK           │
│                                                         │
│ [✗] Cannot assemble: Motor shortage of 5 units        │
│                                                         │
│ Suggestions:                                           │
│ • Reduce production to 95 units                       │
│ • Transfer 5 motors from Warehouse B                 │
│ • Wait for motor delivery (ETA: tomorrow)            │
│                                                         │
│ [Cancel]  [Check Other Locations]  [Assemble 95]     │
└─────────────────────────────────────────────────────────┘

Integration Points

With BOM Module

BOM Definition: Provides component requirements
Component Explosion: Calculates material needs
BOM Validation: Ensures BOM is valid and active

With Inventory Module

Availability Check: Verifies component inventory
Consumption Tracking: Decreases component quantities
Production Tracking: Increases finished goods quantities
Multi-Location Support: Can source from multiple locations

With Transaction Module

Transaction Creation: Creates immutable assembly record
Audit Trail: Complete history of what, when, who, why
Event Generation: Triggers reactive inventory updates

With Finance Module (Future)

Cost Calculation: Standard cost based on components
GL Posting: WIP to Finished Goods journal entries
Variance Analysis: Actual vs standard cost differences

Best Practices

1. Always Check Availability First

// Don't submit assembly without checking
async function initiateAssembly(bomId, quantity) {
  // 1. Get BOM
  const bom = await getBOM(bomId);

  // 2. Calculate requirements
  const requirements = explode(bom, quantity);

  // 3. Check availability
  const availability = await checkAvailability(requirements);

  // 4. Only proceed if all available
  if (availability.allAvailable) {
    await submitAssembly(bomId, quantity);
  } else {
    showShortageReport(availability.shortages);
  }
}

2. Provide Clear Feedback

Show component requirements clearly
Highlight shortages prominently
Offer actionable suggestions
Display real-time availability

3. Handle Partial Availability

Allow production quantity adjustment
Suggest alternate locations
Support split assemblies
Track partial completions

4. Maintain Audit Trail

Record reason for assembly
Capture production run numbers
Link to work orders (if applicable)
Track operator/manager

Performance Considerations

Large BOMs (Many Components)

Load BOM with all components in single query
Check availability in parallel for all components
Use batch inventory updates
Cache BOM data when possible

High-Volume Production

Support batch assembly operations
Queue assembly transactions
Process inventory updates asynchronously
Use optimistic concurrency control

BOM Aggregate - BOM structure
Transaction Aggregate - Assembly transactions
Assembly API - API endpoints
BOM API - BOM management

Last Updated: 2025-10-24 | Status: Active | Version: 1.0

Overview​

Business Context​

Process Participants​

Complete Workflow​

Phase 1: Preparation​

Phase 2: Availability Check​

Phase 3: Assembly Execution​

Detailed Steps​

Step 1: Load BOM and Calculate Requirements​

Step 2: Check Component Availability​

Step 3a: Handle Shortage (if any)​

Step 3b: Execute Assembly​

Step 4: Inventory Updates​

Step 5: Audit Trail​

Business Validations​

Pre-Assembly Validations​

Assembly-Time Validations​

Error Scenarios​

Scenario 1: Insufficient Components​

Scenario 2: BOM Not Found​

Scenario 3: Archived BOM​

User Interface Considerations​

Assembly Screen Layout​

Integration Points​

With BOM Module​

With Inventory Module​

With Transaction Module​

With Finance Module (Future)​

Best Practices​

1. Always Check Availability First​

2. Provide Clear Feedback​

3. Handle Partial Availability​

4. Maintain Audit Trail​

Performance Considerations​

Large BOMs (Many Components)​

High-Volume Production​

Related Documentation​

Overview

Business Context

Process Participants

Complete Workflow

Phase 1: Preparation

Phase 2: Availability Check

Phase 3: Assembly Execution

Detailed Steps

Step 1: Load BOM and Calculate Requirements

Step 2: Check Component Availability

Step 3a: Handle Shortage (if any)

Step 3b: Execute Assembly

Step 4: Inventory Updates

Step 5: Audit Trail

Business Validations

Pre-Assembly Validations

Assembly-Time Validations

Error Scenarios

Scenario 1: Insufficient Components

Scenario 2: BOM Not Found

Scenario 3: Archived BOM

User Interface Considerations

Assembly Screen Layout

Integration Points

With BOM Module

With Inventory Module

With Transaction Module

With Finance Module (Future)

Best Practices

1. Always Check Availability First

2. Provide Clear Feedback

3. Handle Partial Availability

4. Maintain Audit Trail

Performance Considerations

Large BOMs (Many Components)

High-Volume Production

Related Documentation