The Stressometer product line involves software intensive systems, which have been providing rolling mills with accurate online control of the flatness of cold rolled strips for more than 30 years. New generation Stressometer systems are implemented by using SUP (Stressometer unified process) that is RUP/spl reg/ (rational unified process/spl reg/) tailored to fit the Stressometer department's development projects' needs. It facilitates use-case driven, iterative development during which modeling is done via UML. We present the requirements engineering activities that are involved in the SUP, and discuss the problems faced during practice, thus putting forward issues for the attention of research.