The paper presents a modification of the value decision-making approach, named the emergence approach, developed to make decisions in designing innovative complex engineering systems, also called technological innovations of new complex systems. Their design and development is a relevant topic nowadays that cannot be done traditionally due to the necessity to consider innovativeness and the increasing complexity of systems. For design decision making, consideration of innovativeness typically lies in applying mathematical operations, which may lead to a worse understanding of the procedure by all decision-makers as they can include non-technical specialists. This paper proposes another solution based on implementing systems emergent properties. These properties represent higher systems functionality than just the sum of functionalities of systems elements. They allow reaching systems values and consider innovativeness and complexity as complementary features of innovative complex engineering systems. A decision-making approach based on reaching systems values through emergent properties was named the emergence approach. It uses the systems thinking ontology of emergent properties for complex engineering systems as instrumentation for design decision making and avoids deterioration of decision-making procedure understanding by its participants. The paper starts with the overview of approaches applicable to design decision making in technological innovations, continues with the formulation of the emergence approach, highlighting its aspects, and finishes with proof of validity.