Planning for the Unknown: Lessons Learned from Ten Months of Non-participant Exploratory Observations in the Industry Convincing industrial partners to support an exploratory study can be difficult, as benefits are often fuzzy at the beginning. The objective of this paper is to present recommendations for industrial exploratory studies based on our experience. The recommendations are based on ten months of observations during a non-participant, exploratory study with a single industrial partner. This study confirms a number of methodological challenges already identified in the software engineering literature. Based on recommendations from the literature and our own experience, we propose a process for future observational exploratory studies.