[Context & motivation] Feature models are used in product line engineering to document possible product configurations on the feature level. [Problem] In order to quantify the success of adopting feature modeling in practice, we need to understand the industry relevant metrics for feature model evaluation. [Solution] In order to identify the metrics a Goal-Question-Metric approach was used in the context of a case study conducted at Adam Opel AG. [Contribution:] We identified seven goals (quality criteria) we should strive for and evaluate when using feature models. Furthermore, we identified 18 sub-goals, 27 questions and corresponding metrics. The metrics were used to reflect on the feature modeling conducted at the company. © Springer International Publishing Switzerland 2015.