A procedure for scheduling punch presses with restrictions on the sequence of punches

Procedures for generating efficient schedules for punch presses are examined. Technological restrictions force certain groups of holes to be punched sequentially. The proposed methodology is a heuristic procedure which breaks a problem into sub-problems, and solves a travelling salesman problem for each of the sub-problems. Three methods for choosing the starting and ending nodes for the sub-problems are investigated. Computational experience involving the solution of 58 actual industrial punch patterns using a personal computer is presented.