Engineering Design as an Engineering Practice
Engineering design is a defining practice of engineering learning, As defined in the Framework for P-12 Engineering Learning, engineering design practice is supported by core concepts and sub-concepts (e.g. problem framing, design methods, decision making). Both the NGSS and the STEL include design with the NGSS identifying it as "Engineering Design" and the STEL including "design in Technology and Engineering Education" as core disciplinary standard.
Engineering Practices Beyond Engineering Design
The Framework for P-12 Engineering Learning identifies engineering practices as including; Engineering Design, Materials Processing, Quantitative Analysis, and Professionalism (e.g. Ethics, Impacts). The NGSS includes quantitative as one way to optimize solutions during engineering design and also includes some consideration to impacts of design solutions (professionalism) but does not identify materials processing. The STEL suggests "making and doing" (similar to materials processing) as a practice and "Impacts of Technology" and "Influence of Society on Technological Development" (professionalism) as core disciplinary standards. The STEL, however, does not explicitly identify the practice of quantitative analysis.
Core Concepts and Sub-concepts to improve Engineering Practice
The Framework for P-12 Engineering Learning identifies core concepts and sub-concepts to help teachers and curriculum developers create learning opportunities to advance student competency in the engineering practices. The NGSS and the STEL include practices but no accompanying core concepts and sub-concepts.