One of the objectives of implementing and ERP system is to know how much money the company is earning. This can be computed in several costs levels:

- Globaly on the company (using Profit and Lost)
- Per cost center or similar (using Analytic account)

But one may be interested on computing the profit at document/line level. Normally this is computed using the following formulas:

- Profit = Sale Price - Cost Price
- Profit % = Profit / Sale Price = (Sale Price - Cost Price) / Sale Price

We could develop a new module that computes both formulas at sale line.

It will also be interesting to have this information available on document level.

I’m wondering how we should use to compute the Cost Price:

- Saving the current product cost_price on the sale line
- Using the product_cost_history to retieve the product cost_price at the date of the move
- Using the cost_price of the move sale price (only for goods).

To make the feature complete, I think we should also include the profit amount in the Sale Reporting, so one will be able to easly search which customers/products/categories are more profitable.