Operations Research, Vol. 33, No. 4 (Jul. - Aug., 1985), pp. 803-819 (17 pages) We present methods that are useful in solving some large scale hierarchical planning models involving 0-1 variables.

A timetabling problem is formulated as a large integer linear programming problem in 0-1 variables. A solution method based on Lagrangean relaxation coupled with subgradient optimization is presented.