Metal-forming operations such as extrusion, drawing, and rolling offer
many opportunities for operations improvement through better process
understanding and improved planning practices. This paper addresses me
dium-term planning issues in aluminum tube manufacturing operations. F
irst, we identify certain distinctive characteristics-the inherent pro
cess flexibility, close interdependence between successive stages, and
economies of scale-of metal-forming operations, and identify performa
nce tradeoffs across stages. To exploit the strategic potential of pro
cess planning, it must be closely coupled with process engineering eff
orts, and must simultaneously consider the facility's entire product m
ix. In contrast, current process engineering efforts are mainly reacti
ve, focusing on fixing problems at individual operations and with less
emphasis on the interactions between successive stages. Similarly, pl
anning activities are incremental, considering only individual product
s or orders one at a time rather than the entire range of product size
s to be manufactured. By working together, planners and engineers can
develop effective process plans that exploit process capability, and a
dopt proactive process improvement strategies that focus on critical c
onstraints. We describe a medium-term planning model to select standar
d extrusion sizes, illustrate the close linkages between planning and
engineering activities, and identify research opportunities spanning m
anagement science, materials science, and mechanical engineering.