---
title: "Trailers"
space: "Fleet ms"
url: "https://support.aakvatech.com/Fleet MS/trailers"
updated: "2026-07-22"
---

# 🚛 Trailers

## 1. Overview  
The **Trailers** doctype in the *VSD Fleet MS* module is designed to manage all information related to trailers within the fleet system. It enables the organization to track, register, and categorize trailers based on type, specifications, and operational status.

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## 2. Key Features  
- Auto-generation of `trailer_number` from `plate_number` if not manually provided.  
- Unique trailer identification using chassis number and plate number.  
- Attachment of essential trailer documents via a child table.  
- Categorization based on trailer type, tyre specification, and suspension type.  
- Status tracking: *Available*, *Under Maintenance*, *In Trip*.  
- Built-in disabled state control.  
- View includes image field for visual reference.

---

## 3. Pre-Requisites  
- Ensure user has the **System Manager** role or any other role with full permissions on the *Trailers* doctype.  
- Trailer information including Plate Number, Chassis Number, and other required specifications should be available.  
- Document types for attaching trailer documents must be set up (e.g., `Document Attachments` doctype).

---

## 4. Step-by-Step Usage  

**To add a new Trailer:**  
1. Go to **Trailers** from the Fleet module.  
2. Click **New**.  
3. Fill in the following mandatory fields:  
   - Plate Number (unique)  
   - Chassis Number (unique)  
   - Trailer Type  
   - Tyre Specification  
   - Suspension Type  
   - Number of Axels  
   - Manufacturing Year  
4. Optionally, upload an image and attach documents.  
5. The `trailer_number` field will auto-populate with the `plate_number` if left blank.  
6. Select the operational **Status** (default is *Available*).  
7. Click **Save**.

---

## 5. Script Customizations  

```python
class Trailers(Document):
    def before_save(self):
        if not self.trailer_number:
            self.trailer_number = self.plate_number
```

This Python hook in the Trailers class ensures the `trailer_number` is automatically set to the `plate_number` if not provided by the user before saving the document.

---

## 6. Troubleshooting (Common Errors and Resolutions)

| Issue                        | Reason                                   | Solution                                                  |
|-----------------------------|------------------------------------------|-----------------------------------------------------------|
| ❌ *Duplicate Entry*         | Plate Number or Chassis Number exists.   | Ensure both fields are unique for every trailer.          |
| ❌ *Missing Mandatory Fields*| Required fields not filled.              | Fill in all mandatory fields marked with red asterisks.   |
| 🛑 *Document Not Saving*     | Possibly due to custom validation errors.| Check browser console or backend logs for error trace.    |

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## 7. User Roles and Permissions  

By default, the following role has full access:

**System Manager**

| Role           | Read | Write | Create | Delete | Export | Report | Share |
|----------------|------|-------|--------|--------|--------|--------|--------|
| System Manager | ✅    | ✅     | ✅      | ✅      | ✅      | ✅      | ✅      |

> You may customize this in the **Role Permission Manager** as per your requirements.

---

## 8. Key Notes  
- This doctype uses **field-based naming** based on the `plate_number`.  
- Supports tabbed UI for organization — includes “Overview” and “Documents” tabs.  
- Tracks changes via **track_changes** to maintain an audit trail.  
- Set status appropriately to reflect trailer availability or maintenance.

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## 9. What Business Process Pain Point Does It Help Remove  

This doctype simplifies the **management of trailer records** by:  
- Eliminating duplicate registrations through unique identifiers.  
- Automatically assigning trailer numbers, reducing data entry errors.  
- Centralizing trailer information and associated documents in one place.  
- Enhancing operational efficiency by tracking trailer statuses and availability.

---