Welcome to the public repository for the additional content of the paper "Security Engineering in Product-Line Development: Concept and Practitioner Evaluation", published in Springer Communications in Computer and Information Science. Note that this is an extension of the paper "Integrating Security into the Product-Line-Engineering Framework: A Security-Engineering Extension" published at ICSOFT 2025. This repository provides additional information to the conducted study (framework methodology acc. Nickerson et al.) and an initial practitioner survey, including the following file: DATA_EXTRACTION_CCIS.csv: sheet containing all extracted data based on the analysis of 52 papers QUESTIONNAIRE_CCIS.csv: sheet containing all questionnaire data and answer option SURVEY_RESULTS_CCIS.csv: sheet containing data of the 36 participants Requirements for using the data No requirements License for using the data Creative Commons Attribution 4.0 International The Creative Commons Attribution license allows re-distribution and re-use of a licensed work on the condition that the creator is appropriately credited. Further information: https://creativecommons.org/licenses/by/4.0/legalcode