The collaboration of cognitive systems engineers with systems engineers is motivated by the goal of creating human-centered systems. However, there can be a gap in this collaboration. In presentations at professional meetings about cognitive systems engineering projects, we often hear that one or another method of cognitive task analysis was employed in order to inform design. But what software developers need is designs. This is the first of two essays about the gap between the products of cognitive task analysis and the needs of the software engineers. We discuss a success story of cognitive systems engineering for a large-scale system, a project that coped with the practical constraints of time pressure and the challenge of designing for an envisioned world when system elements could not be fully specified in advance. This project relied on a particular product from cognitive task analysis, the abstraction-decomposition matrix, that speaks in a language that corresponds with the needs and goals of the software designers.