HF-MES-manual/en/data_middleground/reverse_traceability.md

# Reverse Direction Traceability

## 1. Function Overview

Reverse Direction Traceability is part of the Basic Traceability module in the MES system's Data Middle Platform. It is used to trace back all raw material information used in a battery starting from **Battery ID** or **Semi-finished Product ID**, and visually displays the complete material composition chain from finished products to raw materials in the form of a tree relationship graph.

**Core Features:**

- Reverse Traceability Query: Enter battery ID or semi-finished product ID to trace back its material composition
- Relationship Graph Display: Display hierarchical relationships between materials in horizontal/vertical tree graph
- Node Location: Support quick location of nodes in the graph by item code, item batch, and process unit
- Data Export: Support exporting traceability tree structure to Excel files

**Feature Screenshot**:
![Reverse Direction Traceability Feature Screenshot](/public/image_en/data_middleground/reverse_traceability/图片：反向追溯功能截图.png)

## 2. Term Definitions

| Term | Definition | Description |
|------|------------|-------------|
| Reverse Direction Traceability | Reverse Direction Traceability, the process of tracing back raw materials from finished/semi-finished products | Opposite to Positive Direction Traceability (tracing finished products from raw materials) |
| Relation Graph | Relation Graph, a visual graph showing parent-child relationships between materials with nodes and connections | Supports both horizontal and vertical display modes |
| Battery ID | Battery ID, unique identifier for batteries in the system | Entry condition for query |
| Finished Product | Intermediate or finished product produced after processing | Identified by green nodes in the graph |
| Raw Material | Original materials used to manufacture finished products | Identified by cyan nodes in the graph |
| Process Unit | Process Unit, standardized process module | Process unit associated with each material node during processing |

## 3. Reverse Traceability Query

### 3.1 Query Description

Reverse traceability inputs battery ID or semi-finished product ID, and the system automatically traces back the feeding records of each process during battery production, constructing a complete material tree relationship diagram from finished products to raw materials.

**Query Conditions:**

| Query Condition | Description | Required |
|----------------|-------------|----------|
| Battery ID/Semi-finished Product ID | Enter battery or semi-finished product ID to trace | Yes |

**[Note]** You can also jump from the positive direction traceability page by clicking the [Reverse Traceability] button in the operation column, and the system will automatically bring in the battery ID and execute the query.

### 3.2 Query Operation Steps

1. Navigate to [Data Middle Platform] → [Basic Traceability] → [Reverse Direction Traceability]
2. Enter battery ID or semi-finished product ID in the search box
3. Click [Query] button
4. The system displays the material relationship graph

**Feature Screenshot**:
![Reverse Direction Traceability Query Conditions Screenshot](/public/image_en/data_middleground/reverse_traceability/图片：反向追溯查询条件截图.png)

## 4. Relationship Graph Display

### 4.1 Graph Description

The relationship graph displays the complete hierarchical relationship from finished products to raw materials in a tree structure. Each node represents a material (finished product or raw material), and connections represent the feeding composition relationship between materials.

**Graph Node Information:**

| Node Information | Description |
|-----------------|-------------|
| Node Identifier | Battery ID/Semi-finished Product ID |
| Item Name | Name of raw material |
| Item Code | Unique identification code of material |
| Item Batch | Batch number of material |
| Process Unit | Code of process unit that the material went through |
| Process Unit Name | Chinese name of process unit |
| Process Code | Specific process code that the material went through |
| Unloading Operator | Operator who unloaded in this process |
| Feeding Time | Start time of material input |
| Completion Time | Time when material processing completed |
| Type Label | Finished Product (green label) or Raw Material (cyan label) |

**Feature Screenshot**:
![Reverse Direction Traceability Graph Node Screenshot](/public/image_en/data_middleground/reverse_traceability/图片：反向追溯图谱节点截图.png)

### 4.2 Graph Mode Switching

The graph supports two display modes, which can be switched via the toggle button at the top of the page:

| Graph Mode | Description |
|------------|-------------|
| Horizontal Graph | Nodes expand from left to right, suitable for deep tree structures |
| Vertical Graph | Nodes expand from top to bottom, suitable for wide tree structures |

**Operation Steps:**

1. Find the graph mode switching area at the top of the relationship graph
2. Click [Horizontal Graph] or [Vertical Graph] toggle button
3. The graph automatically re-renders in the selected mode

**Feature Screenshot**:
![Reverse Direction Traceability Graph Mode Switch Screenshot](/public/image_en/data_middleground/reverse_traceability/图片：反向追溯图谱形态切换截图.png)

### 4.3 Node Location

When there are many nodes in the graph, the node location function can be used to quickly locate the target node.

**Location Methods:**

| Location Method | Description |
|----------------|-------------|
| Item Code Location | Enter item code to locate and center display the corresponding node in the graph |
| Item Batch Location | Enter item batch to locate and center display the corresponding node in the graph |
| Process Unit Location | Enter process unit code to locate the corresponding node |

**Operation Steps:**

1. Find the "Location" area in the left operation panel of the relationship graph
2. Enter item code / item batch / process unit in the corresponding location input box
3. Click the corresponding [Location Confirm] button
4. The graph automatically zooms in and centers the corresponding node

**Feature Screenshot**:
![Reverse Direction Traceability Node Location Screenshot](/public/image_en/data_middleground/reverse_traceability/图片：反向追溯节点定位截图.png)

## 5. Data Export

### 5.1 Export Description

Reverse traceability supports exporting the currently queried material tree structure to Excel files (.xlsx format) for offline analysis and archiving.

**Export Fields:**

| No. | Export Field | Description |
|-----|-------------|-------------|
| 1 | Level | Hierarchical depth of material in tree structure |
| 2 | Battery ID | Battery/semi-finished product ID, with indentation indicating hierarchical relationship |
| 3 | Item Name | Name of raw material |
| 4 | Item Code | Unique identification code of material |
| 5 | Item Batch | Batch number of material |
| 6 | Process Unit | Process unit code |
| 7 | Process Unit Name | Chinese name of process unit |
| 8 | Process Code | Process code |
| 9 | Feeding Time | Feeding start time |
| 10 | Completion Time | Feeding completion time |
| 11 | Category | Finished Product or Raw Material |

### 5.2 Export Operation Steps

1. On the reverse traceability page, first enter battery ID and execute query
2. Confirm graph data has loaded completely
3. Click [Export] button
4. The system generates an Excel file and automatically downloads it to local

**[Note]** Query must be executed before export, otherwise it will prompt "Please enter battery ID".

**Feature Screenshot**:
![Reverse Direction Traceability Export Screenshot](/public/image_en/data_middleground/reverse_traceability/图片：反向追溯导出截图.png)

## 6. Related Functions

| Function | Relationship | Description |
|----------|-------------|-------------|
| Positive Direction Traceability | Inverse Relationship | Tracks which batteries use materials starting from Item Code+Item Batch, can jump to reverse traceability |
| Production Line Management | Data Source | Process data comes from production feeding records of production lines |