Export your Units of Measure.
The default ones are:
product.product_uom_day
product.product_uom_dozen
product.product_uom_hour
product.product_uom_litre
product.product_uom_unit
product.product_uom_cm
product.product_uom_gram
product.product_uom_kgm
product.product_uom_km
product.product_uom_meter
product.product_uom_ton
UPDATE:
You have several problems going on, the data you are providing isn't in the right format and you are also missing data that is required if you import the lines from the BOM.
Looking at the screenshot of your file, you are asking OpenERP to create a BOM with a product instead of a product ID, which is made by using 1 of a product you don't provide details for.
When you export data from a model that has relationships with other models, you must use the XML ID field of those models when linking and any mandatory fields must always be populated.
When exporting via the UI, if you select 'EXPORT ALL DATA' as the Export Type, OpenERP will put an arrow next to any field that represents a relationship and make BLUE any field that is mandatory for an import:
]
In your case you want to import data from the mrp.bom model and you will see blue fields that are actually relationships to COMPANY, PRODUCT and PRODUCT UNIT OF MEASURE.
COMPANY you have correct - "base.main_company"
PRODUCT you have incorrect - you have the name when you need the ID. Export your products to get the ID. It will be in the format "__export__.product_product_XX".
PRODUCT UNIT OF MEASURE you have correct if you use "product.product_uom_unit" but incorrect if you use "Units(s)"
Since you are also importing BOM LINES, you also need to make sure all of the blue fields on that model are provided. For each line on a BOM, you need COMPANY, PRODUCT and PRODUCT UNIT OF MEASURE.
You are providing only type and quantity - but none of the others. The message is referring to the unit of measure for the BOM LINES data that is not provided.
Export your BOM again, but take all of the blue fields that are part of the BOM LINES model.
Ray.