Hard Candy Bagging Line – Throughput Increase

Background

This multinational confectionery company manufactures a leading brand of hard candy. The site had recently installed four bagging lines that had been shipped from another site and reassembled on site by the machinery manufacturer. Each line consisted of a bagging machine, display packing machine and a case packer. The first two lines had been commissioned and were now in production. Each line was operating at less than a third of their capacity due to continual problems with the bagging machines. This was significantly affecting the supply chain and the site was under huge pressure to meet its targeted outputs quickly. Lauras International was asked to coach the site team to increase output to achieve a minimum of 67% efficiency.

Issue/Problem

The bagging machines shipped over were far more complicated than the existing machines on site. They were highly mechanised, using linkages and a ‘walking beam’ to move the bag through the machine (the existing machines used a much simpler rotary head design). Commonly, people rely on previous experience to solve problems, so the first solutions tried are what worked last time. However, in this case the mechanics and operators had no experience of these machines, and were struggling to solve problems – it was not uncommon for a line to be down for more than a shift. This was not due to the ability of the mechanics – nearly everything on the machine was adjustable, and it soon became clear that making an adjustment in one area of the maze of linkages, levers and cams could cause another problem elsewhere. There was no control of the adjustments and it was therefore not obvious what had been adjusted or by how much. Understandably, the mechanics were hugely frustrated of continually chasing problems around the machines with no significant increase in output. Some had even refused to work on the machines altogether, insisting that the only solution was to buy new equipment.

Solution

A team was formed from key areas of the process, including a mechanic, production supervisor and operator. The team then attacked the problem on two fronts; Optimising the output when the machine was running Candy was fed into the bags via a set of counting scales. The maximum speed of the line was restricted by the processing speed of the scales. Setting the machine speed too high resulted in empty bags, an expensive form of material waste, so the machine speed was turned down by the commissioning engineers – but there were still empty bags. The team found out that the machine ran faster at the previous site, without creating so much bag scrap. By optimising the scale settings, the team managing to increase the machine speed by 11% with 100% bag fill rate. Reducing the Downtime As discussed, the majority of downtime was due to excessive diagnosis time identifying the root cause to the problem. In fact, when the team looked into it, they found that there were only 6 main problems (e.g. doubles, where 2 bags overlap in the machine and are sealed together) – but they had never been permanently solved, so they continually occurred. The team used PCS to look at these problems in a more logical way. As the team identified how to deal with them they documented them, and displayed them on the machine to aid problem solving in the future.

Benefits

• The team achieved an almost three fold increase in output per shift, achieving efficiencies of 83%. This enabled the site to meet the supply chain demand, with an additional capacity of 270,000 cases pa freed up for further sales growth.
• There was a labour benefit of $808,000 pa as a result of the increase in efficiency
• There was a material saving benefit of $108,000 pa from the reduction in bag scrap