Welcome to the companion web page for the research paper "Software Variability in Service Robotics," submitted to the special issue on "Software Product Lines and Variability-rich Systems" in the Empirical Software Engineering journal.

Abstract—Autonomous robots artificially replicate human capabilities---including sensing, planning, controlling, and reasoning. Unfortunately, engineering their software, as the core embodiment of this intelligence, has become a bottleneck when building autonomous robots. Software engineers need a diversity of expertise stemming from different disciplines as well as they need to deal with highly heterogeneous hardware. Building highly variable software is one of the core means to address these challenges. Software variability allows reusing software across hardware as well as customizing and adapting robots to their operation environments. However, in the robotics domain, software variability has not been managed systematically yet, indicated by ad hoc practices that challenge the effective reuse, maintenance, and evolution of robotics software. To improve the situation, we need to enhance our empirical understanding of software variability in robotics.

We present a multiple-case study on software variability in the vibrant and challenging domain of service robotics. We investigate the drivers, practices, methods, and challenges of variability from industrial companies building service robots. We analyze the state-of-the- practice and the state-of-the-art—the former via an experience report and eleven semi-structured interviews with industrial experts from two service robotics companies; the latter via a systematic literature review. We triangulate from these three sources and report observations. For each observation we highlight actionable recommendations for our intended audience, namely researchers, tool providers, and practitioners. Finally, we discuss hypotheses explaining and interpreting the various observations. We also offer a comparison of the state of the art with what we observed in our cases in drivers of variability, variability management practices, and challenges faced when managing variability.

On this page, you will find all the material referenced in the study. The replication package is made available in figshare, with DOI 10.6084/m9.figshare.13650362. We provide several artifacts within the same replication package, divided into two categories: "Interview material" and "SLR material." The first contains the artifacts related to our interviews and the latter the artifacts related to our SLR, detailed in the following list:

• A readme file: README.md

Interview material

• Our codebook: Codebook.docx

• The interview guide and used open-ended questions: InterviewGuide.pdf

• A description of the cases stated by our interviewees to illustrate drivers of variability, management practices, and related challenges: cases.pdf

• A description of the cases stated by our interviewees to illustrate drivers of variability, management practices, and related challenges: bapo.pdf

SLR material

• The protocol followed for the SLR: protocol.pdf

• The data extraction template we used for noting relevant information from the search results, one for each digital library: data-extraction-ACMDL.xlsx, data-extraction-SCOPUS.xlsx, and data-extraction-IEEE.xlsx.

• The results from the automatic search in both libraries, i.e., Scopus and ACM DL. It includes a list of all publications processed in the survey, and their exclusion- and inclusion-stage: search-results-ACMDL.xlsx, search-results-SCOPUS.xlsx, and search-results-IEEE.xlsx.

• The search strings for each digital library: search-strings.txt.