Work Domain Analysis (WDA) and task analysis are methods that can be used to develop complex systems that support human operators. Task analysis can be used to describe the nominal tasks of many complex safety critical systems which are also highly proceduralized. However, complex systems may require human operators to have a greater understanding of the system's dynamics than can be obtained from procedures derived from a task analysis. This is particularly true when off-nominal events occur, for which there is no procedure. By concentrating on the constraints in the work domain instead of tasks, work domain analysis can complement task analysis by supporting operators during off-nominal events that do not have any predescribed procedures. The goal of this study was to use WDA and two forms of task analysis to derive interface and procedure modifications for a new aviation concept called interval management. Interval management is a new concept whose goal is to increase runway throughput by enabling aircraft to achieve a precise interval behind a lead aircraft. This study used data from a human-in-the-loop study conducted at NASA Langley Research Center to develop a Hierarchical Task Analysis (HTA), Control Task Analysis (CTA), and WDA. The HTA was used to describe a nominal set or procedures, the CTA was used to describe strategies pilots could use to make decisions regarding the IM operation, and the WDA was used to determine representations and procedures that could convey complete and accurate knowledge of interval management to the flightcrew.