Engineering systems design projects require the integration of multiple technical systems. As a result, engineering systems design project teams are often multidisciplinary. The engineering design functions involved in such projects are also diverse and can include structural design, environmental control design, electrical design, etc. This study explored the relationship between different engineering design functions and the presence or absence of risk indicators in system level design projects. A risk indicator is a particular state of affairs that has potential predictive power related to the likelihood of a risk occurring during the life cycle of an engineering design project. Interviews with members of the functional groups involved in eleven different engineering design projects were conducted using critical incident methodology. Interview notes were transcribed and coded to identify risk indicators. These projects were categorized as having varying levels of functional complexity based on the number of different engineering functional departments involved in the project. A comparative analysis of risk indicators was completed to identify those indicators that appear to be related to the level of functional complexity. Engineering project managers can utilize the results of this research to develop appropriate risk mitigation plans for engineering design projects based on the level of functional complexity.