The attainable region (AR) concept uses a geometrical procedure to determine the boundaries of the region that include all possible reactor products for a known feed condition. The procedure also allows the choice of reactor(s) and the sequencing of these reactors to maximize the selection of reactor products in terms of predefined objective functions. It is also possible to derive the process operating conditions commensurate with an optimum objective function. The AR concept currently is being applied to industrial applications, and in this paper the concept is used to study the manufacture of butadiene by the oxidative dehydrogenation of 1-butene. Process operating conditions, specifically the partial pressure of oxygen, are reviewed. The reactors discussed in this paper are the fixed-bed reactor and the inert porous membrane reactor. A candidate AR for the system butene-butadiene is proposed.