This paper addresses the following question: how does the coordination
challenge faced by managers change over the life of time bound projec
ts such as product design, We use coordination structure, an approach
to modeling organizational situations that highlights concurrent respo
nsibility interdependencies rather than the more traditional task inte
rdependencies, We explain coordination structure and use it to capture
the responsibility interdependencies in a sample of complex system de
sign projects drawn from two different organizations, We use this data
: to illustrate the differences possible in the responsibility interde
pendencies that can exist within design projects from different organi
zations and at different project key points; to identify a set of four
basic modules, or groupings, of responsibility interdependencies usef
ul for modeling design organizations; and to generate a set of testabl
e hypotheses on how the coordination challenge faced by project manage
rs can vary between organizations and over project key points.