# Create new models from existing dimensions and measures

> This document describes how to use AML Extend to create a new data model from existing models

You can use [AML Extend](/reference/aml/extend) to define groups of reusable dimensions/measures, and combine them to create a new data model on the fly chaining extensions together.

```tsx

// highlight-next-line
PartialModel revenue_metrics {
	measure gmv { ... }
	measure mrr { ... }
	measure arr { ... }
}

// highlight-next-line
PartialModel location {
	dimension city_name { ... }
	dimension country_code { ... }
}

// highlight-next-line
PartialModel date {
	dimension created_at { ... }
	dimension updated_at { ... }
}

// Chaining multiple extends
// highlight-next-line
Model merchant_full = company
	.extend(revenue_metrics)
	.extend(location)
	.extend(date)

// highlight-next-line
Model merchant_secure = company
	.extend(location)
	.extend(date)

```