> For the complete documentation index, see [llms.txt](https://docs.dataloy.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.dataloy.com/release-8.28/voyage-management-system/step-by-step-guides/voyages/maintain-voyages/operating-costs-opex.md).

# Operating Costs - OPEX

## Operational Expenditure (OPEX) Overview

Shipping companies operating owned vessels incur ongoing costs that have nothing to do with freight income or hire rates — crew wages, lubricating oil, insurance, vessel retrofitting, and similar day-to-day running expenses. These are known as **Operational Expenditure (OPEX)**.

OPEX sits below the TC Result line in VMS. It does not affect the Time Charter Equivalent (TCE) or TC Result, but it does reduce the final Voyage Result. This makes it essential for Operations Controllers and Finance users who need to report vessel profitability accurately.

**Voyage Result formula:**

```
VOYAGE RESULT = TC Result
              − TC Hire Net
              − Ballast Bonus Net
              − OPEX
              + Backhaul Saving
              − CVE TC In
```

***

### How OPEX Is Structured in VMS

OPEX is defined at two master data levels and then stamped onto the voyage:

**Vessel Type** is the starting point. Default OPEX rates are defined here and represent the baseline cost structure for all vessels of that type — crewing, lube oil, insurance, and so on.

**Vessel** has its own OPEX list (under the Operating Expenditure tab) which operates independently once populated. When a vessel is assigned to a voyage, the system stamps the vessel's OPEX lines onto the voyage.

**Voyage** holds the stamped OPEX lines and uses them to calculate the total OPEX for that voyage. Lines on the voyage can be added, edited, or deleted independently without affecting the vessel or vessel type records.

> **Note:** Changes made to OPEX rates on the Vessel Type or Vessel after stamping do not cascade automatically to existing voyages. Each level is independently editable once copied.

***

### OPEX Line Fields

Each OPEX line carries the following information:

| Field                     | Description                                                                                                                                        |
| ------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Opex Cost Code**        | Reporting code. Available on Vessel Type and Vessel records only.                                                                                  |
| **Opex Cost Description** | Label for the cost category, e.g. "Crewing" or "Lube Oil".                                                                                         |
| **Daily Rate**            | The cost rate in the OPEX currency, applied per voyage day.                                                                                        |
| **Currency**              | The currency in which the rate is expressed. If this differs from the voyage currency, conversion uses the exchange rate at the voyage start date. |
| **From Date / To Date**   | The validity period for this rate.                                                                                                                 |
| **Stock Account**         | The accounting stock account reference used when posting transactions.                                                                             |
| **Cost Account**          | The accounting cost account reference used for document lines.                                                                                     |
| **Comment**               | Free text remark.                                                                                                                                  |

***

### OPEX Calculation

Total OPEX for a voyage is calculated as:

**Total OPEX = Σ (Daily Rate × Voyage Days)** across all active OPEX lines on the voyage.

The calculated total is stored in the voyage and feeds directly into the Voyage Result.

OPEX recalculates automatically whenever any of the following change:

* The vessel assignment on the voyage
* Total voyage days
* Offhire days (where the offhire record includes an OPEX deduction flag)
* Any OPEX line on the voyage is added, edited, or deleted

***

### Offhire and OPEX

When a vessel goes offhire, OPEX continues to accrue. If the offhire record has the deduction flag set — **Deduct from Operational Cost** — the OPEX for that offhire period is deducted from the appropriate account based on voyage type:

| Voyage Type              | Deduction Target |
| ------------------------ | ---------------- |
| VC Voyage (owned vessel) | OPEX cost        |

All active OPEX lines on the voyage apply to offhire periods. If the OPEX currency differs from the voyage currency, conversion is applied before deduction.


---

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