Hello. I have a similar issue. I'm storing products for a customer and we are repairing them. lets say in this example we are the car repair shop. I want to be able to track all of my customers individual cars (create a new unique product for each car) and then add the service and product that we did on the car to repair it. Then after a year or two I'd like to summerize all the repairs and services on each individual car. we are repairing each product every month so for us it makes sense to be able to track this. In the report it would then say that for "Car Product 1" we have washed it 5 times, repair the tires 2 times, repair the seats 5 times and used "spare part 1 (spare part)" during the last 1 year when in fact the car was handed in on 5 different occasions. 

With the repair module from Odoo its not possible to track the correlation and the sum of all services done on a product. maybe with manufacturing/BoM it can be done?

If you want to track expenses related to specific products or inventory items in Odoo, you can use the "Bill of Materials" (BoM) feature along with the "Manufacturing" module. Here's how you can achieve this:

1. Enable the "Manufacturing" module in Odoo if it's not already enabled.

2. Create a product for each individual car in your inventory. Each car will have its own unique product.

3. Create a BoM for each car product to include the expenses related to that car. Go to "Manufacturing -> Master Data -> Bill of Materials" and create a new BoM for each car product.

4. In the BoM, add the car product as a component and specify the quantity as 1.

5. Add additional lines to the BoM for each expense related to the car. For example, you can create separate products or accounts for repairs, cleaning, etc., and add them as components in the BoM with the appropriate quantities and costs.

6. Save the BoM.

By using this approach, you can create a BoM for each car product that includes the expenses associated with that specific car. When you manufacture or produce the car using the BoM, the expenses will be allocated to the final product.

You can then view the cost analysis or the cost structure of each car product to see the total cost, including the initial purchase price and the associated expenses. This will allow you to have a comprehensive overview of how much each car has cost you.

Additionally, you can use the reporting and analytic features in Odoo to analyze the costs and expenses for different products, track profitability, and generate financial reports based on the product's cost structure.

Note that the exact steps and fields may vary depending on the version of Odoo you are using, but the general concept of using BoMs and manufacturing to track expenses should be applicable.