With the increasing importance of teaching STEM to young students, the engineering design process (EDP) has become a popular learning platform in K-12 STEM education. The engineering design process guides students in solving engineering problems, but there is a lack of understanding of how students utilize this process. In this study, we explored how iterative design activities form procedural patterns of the engineering design process using sequential analysis. We videotaped 48 engineering design sessions via the Concurrent Think-Aloud (CTA) protocol from elementary students grades 3-6 in the USA. The data was coded using Halfin's codes. The sequential analyses identified the statistical significance of patterns from the repetitive design activities. The results indicate (1) there were two iterative recursions in the problem and solution phases, (2) questioning was a gateway to designing, (3) modeling and predicting occurred with designing, and (4) managing bridged the problem and solution phases. The study also found that different design contexts yield distinctive procedural patterns. This result implies that engineering educators need to understand the proper use of the design process model.