Many companies have attempted to introduce Lean practices in product development to gain competitive advantage in today's global market place. However, the application of Lean outside the factory floor is not straightforward-especially when it is introduced in functional areas that differ significantly from manufacturing, such as in the multifaceted context of System Engineering (SE). In this article, we investigate the extent to which SE companies are engaging in Lean product development, and the degree to which various lean practices and capabilities are implemented. The overall goal is to determine how SE companies compare to companies in other industrial sectors, and thereby gaining new insights into strategies for more contextual implementation of lean in engineering functions. An extensive literature review is conducted to synthesize prior research with regard to the principal components of Lean when applied in product development. The extract from the literature study is combined with the author's industrial experience and hypothetical reasoning to build a framework consisting of six principal Lean components, including Customer Value, Knowledge Transfer, Continuous Improvement, Standardization, Stabilization and Culture. Each of these is divided into a set of practice and capability characteristics collectively constituting the component as a whole, forming the basis for a survey for lean maturity. A survey is conducted in the Norwegian manufacturing industry to determine Lean practices from the construct of the generic model as basis. The survey was answered by 297 respondents from 56 companies, providing the opinion of individuals as to where they place their current practices and capabilities on alean maturity scale for each question, including a supplemental set of performance and productivity related assessment items. Results indicate that there seem to be explanations rooted in marked and project characteristics, for the significant differences between perceived Lean performance in Systems Engineering versus the other sectors, especially Automotive, when talconsidering Customer Value and Project Performance. In between these categories this study reveals a potential for the Systems Engineering industry to improve upon the way organizational learning is managed to develop and sustain a culture for continuous improvement. Findings and discussions underline that Lean has a stronger foothold, based on history and market conditions, in the Automotive industry, as to how organizations effectively execute development projects.