Navigating Heterogeneous Variability: Strategies and Insights from the Industrial Technology Division of ZF Friedrichshafen AG

Efficient variability management is a key capability for industrial companies developing complex, configurable systems, especially those with a wide range of product lines and custom solutions. This experience report presents the approach taken by the Industrial Technology division of ZF Friedrichshafen AG to manage variability in both system and software development. The division serves a broad spectrum of markets and applications. This diversity introduces a high degree of heterogeneity at multiple levels, ranging from domain-specific engineering requirements to cross-departmental coordination challenges. Further specific challenges include reuse across different platforms and projects, tailoring solutions to diverse OEM demands, supporting long product lifecycles, and accommodating both legacy and next-generation systems. This experience report aims to contribute to the collective knowledge of the systems and software product line engineering community by offering a detailed, practice-oriented view of heterogeneous variability management. We explore how product software reuse is becoming increasingly essential and how variability management practices must evolve to support scalable reuse across both embedded software and higher-level platforms. We discuss key drivers, requirements, and approaches for heterogeneous variability management and distill a set of lessons learned to guide other organizations on their variability management journey.