Software product-line engineering is arguably one of the most successful methods for establishing large portfolios of software variants in an application domain. However, despite the benefits, establishing a product line requires substantial upfront investments into a software platform with a proper product-line architecture, into new software-engineering processes (domain engineering and application engineering), into business strategies with commercially successful product-line visions and financial planning, as well as into re-organization of development teams. Moreover, establishing a full-fledged product line is not always possible or desired, and thus organizations often adopt product-line engineering only to an extent that deemed necessary or was possible. However, understanding the current state of adoption, namely, the maturity or performance of product-line engineering in an organization, is challenging, while being crucial to steer investments. To this end, several measurement methods have been proposed in the literature, with the most prominent one being the Family Evaluation Framework (FEF), introduced almost two decades ago. Unfortunately, applying it is not straightforward, and the benefits of using it have not been assessed so far. We present an experience report of applying the FEF to nine medium- to large-scale product lines in the avionics domain. We discuss how we tailored and executed the FEF, together with the relevant adaptations and extensions we needed to perform. Specifically, we elicited the data for the FEF assessment with 27 interviews over a period of 11 months. We discuss experiences and assess the benefits of using the FEF, aiming at helping other organizations assessing their practices for engineering their portfolios of software variants.

软件产品线工程可以说是在应用程序领域中建立大量软件变体组合的最成功方法之一。但是，尽管有这些好处，建立一条产品线仍需要对具有适当产品线架构的软件平台，新的软件工程流程（域工程和应用工程），具有商业成功的产品线远景的业务战略进行大量的前期投资。和财务计划，以及重组开发团队。此外，建立完整的产品线并非总是可能或不希望的，因此组织通常仅在认为必要或可能的范围内采用产品线工程。但是，了解采用的当前状态，即 组织中产品线工程的成熟度或性能具有挑战性，同时对于引导投资至关重要。为此，文献中提出了几种测量方法，其中最突出的一种是近二十年前引入的家庭评估框架（FEF）。不幸的是，应用它并非一帆风顺，到目前为止，尚未评估使用它的好处。我们提供一份将FEF应用于航空电子领域的9个中型到大型产品线的经验报告。我们讨论了如何定制和执行FEF，以及我们需要执行的相关修改和扩展。具体来说，我们在11个月的时间内进行了27次访谈，得出了FEF评估所需的数据。我们讨论经验并评估使用FEF的好处，