A decision making tool is proposed to evaluate assembly costs of micro-products (< 1 dm(3)) and to compare different assembly strategies for a given product or product family. The tool takes into account equipment costs as well as running costs, for manual and automatic assembly. Its specificity lies in its ability to deal with different production mixes and production volumes over the life cycle of the product family. The underlying concept of the tool is that the cost of a given assembly function (or process) is constant for different technical solutions. This paper describes a cost evaluation for reconfigurable, manual, automatic or semiautomatic assembly lines, and shows its easiness of use through a simple test case.