# engine.solver.EconomicsModel { #mlsysim.engine.solver.EconomicsModel }

```python
engine.solver.EconomicsModel()
```

Calculates Total Cost of Ownership (TCO) including Capex and Opex.

Combines hardware costs, energy consumption, and maintenance
into a single financial model for the fleet.

Literature Source:
1. Barroso et al. (2018), "The Datacenter as a Computer: An Introduction
   to the Design of Warehouse-Scale Machines."
2. Patterson (2004), "Latent Bugs in Common-Case Software." (TCO Foundations)
3. Meta (2024), "Sustainable AI Infrastructure at Meta Scale."

## Methods

| Name | Description |
| --- | --- |
| [solve](#mlsysim.engine.solver.EconomicsModel.solve) | Calculates the TCO for a fleet over a specified duration. |

### solve { #mlsysim.engine.solver.EconomicsModel.solve }

```python
engine.solver.EconomicsModel.solve(
    fleet,
    duration_days,
    kwh_price=None,
    datacenter=None,
    grid=None,
    mfu=1.0,
    amortization_years=3.0,
    infrastructure_multiplier=cal.DEFAULT_INFRASTRUCTURE_MULTIPLIER,
)
```

Calculates the TCO for a fleet over a specified duration.

#### Parameters {.doc-section .doc-section-parameters}

| Name          | Type        | Description                                                      | Default    |
|---------------|-------------|------------------------------------------------------------------|------------|
| fleet         | Fleet       | The hardware cluster configuration.                              | _required_ |
| duration_days | float       | Operation duration in days.                                      | _required_ |
| kwh_price     | float       | Price of electricity per kWh.                                    | `None`     |
| datacenter    | Datacenter  | A specific datacenter profile.                                   | `None`     |
| grid          | GridProfile | A specific grid profile.                                         | `None`     |
| mfu           | float       | Model FLOPs Utilization (0.0 to 1.0) impacting energy footprint. | `1.0`      |

#### Returns {.doc-section .doc-section-returns}

| Name   | Type             | Description                                             |
|--------|------------------|---------------------------------------------------------|
|        | Dict\[str, Any\] | Financial metrics including CapEx, OpEx, and total TCO. |
