Sequencing and Scheduling in the Sheet Metal Shop

Abstract

Introduction HistorySheet metal operations have been in existence since 8000 B.C. (Fries-Knoblach, 1999). Due to its long history, sheet metalworking is, unfortunately, often seen as archaic and uninteresting. That metal sheets can be transformed with the aid of robust machines into fancy consumer products with tight tolerances is inconceivable to many. Yet, sheet metal operations are used for producing both structural components and durable consumer goods. Nowadays, sheet metal parts are widely present in different daily life products. During the past decades, scientific research in the field of sheet metal operations has been booming and international conferences on different sheet metal topics attract numerous attendants. Both industry and the academic community recognize the importance of continuing improvement in sheet metal operations. Thirty years ago, the rapid advance of computer systems triggered the introduction of automation in manufacturing environments. Also for sheet metal operations the use of computer systems has become indispensable to survive. Computer aided design (CAD) and computer aided manufacturing (CAM) systems are widely present in sheet metal production environments. At the earliest design stage, CAD systems are used to computerize the whole process of drawing and redrawing the desired part. Most modern CAD systems allow to build up a part from several re-usable 3D components, thus automating to a large extent the time consuming design process. The use of computers has also entered the manufacturing stage through computer aided manufacturing. The CAD file is converted into a sequence of processes for manufacture on a numerically controlled (NC) machine. The use of computers helps operators in automating different steps of the production process. As far as planning is concerned, most attention is focused on the computerization of sheet metal process planning. Production planning proper received much less attention due to a long tradition of experience-based production planning. Scope of the researchIf one queries the internet for sheet metal operations, numerous entries on processes are found, for instance on laser cutting, punching, deep drawing, bending, incremental forming,

Cloud manufacturing – Scheduling as a service for sheet metal manufacturing

“…Local search is applied enable a straightforward way to determine optimal solutions after a limited computational effort. However, the solution is good but not necessarily optimal (Verlinden et al, 2007).…”

“…The sheet metal industry has focused on the automation of cutting, punching, forming, shearing and nesting processes for sheet metal parts (Wang & Bourne, 1997;Verlinden et al, 2007). Sheet metal manufacturing line consists typically of several automated machines connected together, such as automated warehousing management system (WMS), laser cutting machines; punchingshearing machines, conveyors, robots and bending machines.…”

Construction heuristics for generating tool paths for laser cutters

“…A typical production process consists of designing parts, nesting the parts on metal sheets, cutting the parts from the sheets and if there are three-dimensional parts, bending the parts. Verlinden et al (2007) describe a set of integrated production scheduling methods to minimise the total cost incurred for the entire production process. One of the results is the assignment of parts to a metal sheet after which CAM software executes the actual nesting and generates a cutting path.…”

Marker planning for fabric cutting with sewing schedule constraint in mass customization context

“…The combined model objective is to minimize total setup time appearing in air bending operation. B.Verlinden, et.al, [57] proposed another integer programming (IP.) model to deal with the same problem in sheet metal factory.…”