This chapter has two purposes. First, we contrast two approaches to instructional design—the traditional Instructional Systems Design (ISD) process and an alternative view known as Functional Design Layering (FDL). In our review, we describe the background of each approach, the problem(s) each approach attempts to solve, and the types of decisions each approach prepares instructional designers to make. Second, we show how these different approaches play complementary roles in the practice of instructional design. When considered together, they offer a more robust conception of how instructional designs can be created. Essentially, ISD focuses on design process at the expense of internal design structure, whereas FLD focuses on internal design structure and proposes a naturalistic view of design decision order that is more closely aligned with actual designer practice. Considered together, these contrasting approaches become mutually strengthening, providing the designer with a wider range of design questions and design process options.