Nothing better and cheaper has yet been found than industrial cardboard packaging, whether it is for packing TV sets, fridges, cans of tomato paste or bottles of detergent. Although it has been present for many years at the final point of the industrial process, these boxes need constant improvements in their manufacturing particularly to reduce the quantity of leftovers without any loss of quality. It was thinking of solving this problem in relation to cutting sheets of cardboard that mathematician Sóstenes Lins, a professor at the Federal University of Pernambuco (UFPE), created the Conjug software, already in use in industries from all over Brazil. The success of this product is one of the most emblematic examples of a study generated in an academic environment that wins market and brings important contributions for the productive system. The calculations for cutting the cardboard previously used to be done manually. “All that was used was a calculator and common sense”, Lins reveals.
The difficulty is that there are, literally, billions of possibilities for cutting the large rectangle to which the roll of cardboard is reduced, when used to make boxes. “And human beings can only arrive at two, three, or ten at the most. ” Conjug is based on an algorithm – a process for calculating – conceived in 1986, in partnership with students for a master’s degree. A member of the Brazilian Academy of Sciences (ABC), he tells how he created the algorithm thinking of reducing the losses of paper. “I just did not imagine that it was something that was innovating. I thought that Brazilian companies would be using something similar”, he recalls. In December of the next year, he sold the first version of the software to Klabin’s factory in Pernambuco. Today, Conjug is used in ten of the company’s units, where they produce pulp, paper and boxes of corrugated cardboard.
Lins estimates that Conjug is employed in over 10% of the corrugators in Brazil, a kind of machine that makes corrugated cardboard. To market the software, the professor set up the LinSoft company, managed by his wife. His son Lauro Didier Lins, who is studying for a doctorate in Computational Mathematics at UFPE, is responsible for the technical part, along with a sister of the professor, Nadja Lins, an electrical engineer and network administrator at UFPE’s Information Technology Center. Besides Klabin’s factories, the software is used in paper industries in the states of Amazonas, São Paulo and Ceará.
Another system created by the mathematician’s team, and one that transcended the limits of the university, is S-Plex, used in cutting coils of steel. Unlike the cutting of cardboard, in which the sheets are separated for making the boxes, the coil of steel is sliced into strips. The process is like cutting a Swiss roll. Some slices are thinner, like those supplied to hair-grip manufacturers, and others are thicker, intended for making cleavers (a kind of knife). Cutting steel is also part of an industrial sector where the calculations used to be done by hand. The software has been in use since November 2002 at Armco, an industrial concern that produces sheets of steel in São Paulo and Manaus. The man responsible for the company’s Integrated Planning sector, Edson José Lopes, estimates that the use of the system has brought about a 20% reduction in scrap. “I am eliminating a critical point by adopting S-Plex”, he sums up.
LinSoft was created in 1992. Without any competition, the software went so far as to plan the cutting of cardboard boxes in 20% of the factories in the country. “We had no competitors at the beginning, but today they exist”, Lins has found out. This calls for a constant evolution of Conjug. Today, it covers work in a network and is not just focused on reducing losses with paper. It also takes profit into account, since it is capable of planning all the production. “It is possible to arrange the cutting according to the orders and to their urgency”, Lins explains. Another variable included in Conjug is the paper inventory. “Proper planning of production avoids losses and improves productivity”, he adds.
The Lins family company is also developing software aimed at packing boxes. It is called ExpedPlex, and it plans the way boxes are arranged on pallets, in containers, and on trucks. Pallets are the wooden platforms on which the cargo is piled up for transport and storage. The system is based on four algorithms. One of them generated a publication in the European Journal of Operations Research. In this case, the objective is to save space. Sóstenes calculates that the addition of from 5% to 8% in the volume stowed trucks generates a saving of one less truck for each 15 to 20 trips.
Another software related to the organization of boxes is PalletZoom, copies of which were acquired by the Bompreço supermarket chain. The system is capable of defining how best to arrange the packaged products on the pallets. To do so, the user just has to supply details of the dimensions of the boxes and of the pallets. The machine calculates how the cargo is to be stowed and provides an illustration of how the boxes should be piled up. Lins explains that he created PalletZoom not only to make for better storage, but also greater speed in transporting the products, because the arrangement allows for a larger number of boxes on the pallet.
If today LinSoft’s products are in use all over the country, at the beginning Professor Lins had great difficulties, in particular to convince the people from industry to accept the product. “I started to look for companies interested in using new methods for trying to reduce losses from cutting. And it was a struggle to convince people”, he recalls. The first company that he tried was Ponsa, of the Klabin group, in Pernambuco, back in 1986. “They put me in contact with their branch in Rio de Janeiro. Afterwards, in December 1987, we agreed that I would perfect the software and that they would buy a version. There were more or less six or seven months of development. Klabin bought the first version of Conjug, but only used the software for two months.” At the time, Lins was not contacted by the company and only found out later that they had desisted.
The professor attributes the initial lack of success to technical limitations. “Computer were very bad, they had little memory and were slow. The technology for developing software also left a lot to be desired. The interfaces were no good”, he remembers. Even so, the program worked. “It optimized, it cut down the leftovers”, he guarantees. After the attempt with Klabin, Lins “forgot” Conjug for three years. “I took care of my own life, doing theoretical mathematics and publishing my papers”, says he, the author of 30 articles published in scientific magazines with an international circulation.
In July 1991, technicians from Ponsa once again approached him. “There was a firm intention of really using the program, and this time it worked out.” In 1993, Klabin decided to adopt the software at their factories in Piracicaba and Jundiaí. “Afterwards, it was the turn of the factory in the city of Rio de Janeiro, in February 1994. Then all the branches of the company came”, he tells. With the success at Klabin, several other companies became interested. In 2001, LinSoft was present in over 20% of the companies in the corrugated cardboard market.
Mathematician Paulo Seixas Avino, a business analysts with Klabin, says that Conjug guarantees agility in the process, reliability in the results, and, above all, a reduction in the losses of raw material, which can reach 2% of the production. For Lins, the software’s success is not just related to the theoretical aspect of the product, but also to an interface that is pleasing to use and gives the users confidence.Republish