Sheet metal cutting using lasers is ubiquitous in the industry, and is
used to produce everything from home decorations to excavator
scoops. Metal waste is costly for the industry, both in terms of
money, but also in terms of an increased environmental
footprint. Tomologic develops a unique optimisation system that can
reduce this waste drastically. This paper presents a CP approach to
the Laser Cutting Path Planning Problem (LCPPP), a very hard important
sub problem within the Tomologic optimisation system. A solution to
the LCPPP is, given a packing of some details on a metal sheet, an
ordering of the cuts necessary to separate the details from the
sheet. The problem is complicated by physical factors such as heat
from the laser beam, or details moving or flexing. In the paper, we
explain the problem in detail and present our CP approach that we
developed for solving the problem. The possibility (in CP) of custom
search heuristics turned out to be crucial to be able to solve the
problem efficiently, as these could be made to guide the search to
good first solutions.