A careful user needs assessment is one of the essential factors in the successful development of new products and services. Strategies for need assessment are often used to assess and select ideas during the idea generation phase of the new product development process. However, there is still a large gap between evaluating ideas and evaluating the performance of a product according to the user's needs. To address that gap, this paper aims to formulate propositions and identify key insights on how to evaluate the performance of new products according to the user's needs from a design perspective. Towards our aim, we conducted 10 in-depth interviews with design thinking professionals from Hasso Plattner Institute (HPI) in order to identify relevant concepts that could be used for product assessment. The findings provide preliminary results of how to link need assessment in product performance and idea selection in design thinking. This research intends to contribute to the literature by advancing the discussions on need assessment in new product performance by adding new perspectives from design.