A hybrid approach for concurrent layout design of cells and their flow paths in a tree configuration

The layout design of multiple-cell automated manufacturing systems includes cell layout design and flow path layout design. Traditional layout methods often treat these two as separate problems and the sequence for solving th em is usually cell layout first and flow path layout later. However, approa ches of these kinds have one major drawback, that is, they may produce cell layouts that are awkward or difficult for designers to conduct flow path l ayouts, or cell layouts that do not turn out to be as good as expected afte r flow path layouts have been performed. Other drawbacks of traditional lay out methods include irregular shapes of cells, inaccurate calculations of f low distances, etc. This paper addresses the layout problem of cells and th eir connecting flow paths in a tree configuration. The proposed layout proc edure is designed to avoid the aforementioned drawbacks of traditional layo ut methods by emphasizing concurrent layout design of cells and flow paths. It combines a search algorithm and mathematical programming models. The se arch algorithm has a backtracking procedure that allows one to explore alte rnative layouts, while the mathematical programming models help one obtain accurate layouts of cells and flow paths. The proposed layout procedure als o interacts with designers and allows designers to include their qualitativ e consideration into the layout design. As a result, one can obtain more ac curate and good-quality layouts with the proposed layout procedure.