Structurally reducing production disturbances and its root causes
That headline will strike a chord with just about everyone in the industry. And raise questions. How exactly do you reduce production disturbances and its root causes, and increase overall equipment effectiveness (OEE)? How do you make sure that these are not just ad-hoc solutions, but part of an ongoing process? And how do you make the most effective use of people and systems in that process? At cement manufacturer and supplier ENCI, part of the HeidelbergCement Group, Production Manager Andre Hoogervorst has been addressing these issues head on. And with success. “A saving of about €50,000 a year by finding a permanent solution for a leaking valve is just one example,” he says. Hoogervorst recently shared his experiences with colleagues at other plants, and now he has accepted our invitation to pass them on to you.
With the implementation of ShiftCliq, the logbook module of Unite, ENCI is annuallly saving € 50,000. For production manager Andre Hoogervorst this module means:
• Continuous overview:
working quicker and more
• All information is filed,
even at the lowest level
• OEE Toolkit, SAP and
Clarity and understanding
ENCI uses a number of different systems to facilitate the various steps in its continuous improvement process. That began with OEE Toolkit and SAP, but later expanded with ShiftCliq, the electronic logbook application from iBanx. The need for such a system arose in part because it had been difficult to review earlier operator experiences in the event of disturbances. ENCI also wanted better task records: in the past details had been passed on verbally, on paper or in Excel spreadsheets, which meant that they were not always clear and sometimes disappeared under a pile of paperwork.
ShiftCliq provides each shift with clear guidance on exactly what to do and how to do it (instructions), as well as showing whether tasks are followed up. At ENCI that has been put at the heart of the production process, says Hoogervorst. “Our production and maintenance team leaders sit down every morning with the shift co-ordinators and go back over the past 24 hours – or 48 hours after the weekend. There is constant monitoring, retrievable at the touch of a button, which makes it far quicker and easier to respond to problems.” Another advantage is that managers can see what is happening in the factory remotely, and all the information gathered – from the most basic level – is saved. Whenever an operator enters data, it is available not just to his line manager but throughout the company. So although the system is primarily a production log, the technical departments can also access it to read important information. “We’ve seen a downward trend in the number of production disturbances,” declares Hoogervorst, “and that’s thanks to ShiftCliq.”
The logbook is reviewed daily, and every week the top three problems are examined in more detail. To decide which problems need to be tackled first, Hoogervorst applies Pareto analysis, also known as the 80:20 rule. This works on the principle that clearing 20 per cent of the disturbances will solve 80 per cent of your problems, and according to Hoogervorst is a “golden rule” in his industry. But it is important to know which 20 per cent of the disturbances to tackle. The combination of OEE Toolkit, SAP and, as an analytical tool, ShiftCliq plays a role in determining that.
Smart system interfaces
By ensuring that ShiftCliq was implemented with the same systematics and coding pattern for primary groups as SAP and OEE Toolkit, the applications now connect seamlessly and provide more data than was previously available. “We now measure not just the availability rate per unit and which primary groups are causing the most maintenance issues,” Hoogervorst explains, “but we also use the information from ShiftCliq to see in detail – at individual component level – what is going on during operations. From that we can often determine the causes of disturbances.”
Analysis of disturbances saves ENCI €50,000
The ability to analyse situations in a straightforward manner can lead to big savings. Take the example of a disturbance caused by a leaking valve at ENCI. “Pareto analysis revealed that this was one of the top 20 per cent of problems at the time,” Hoogervorst says. “So we needed to look at it more closely. OEE Toolkit revealed that the disturbance was in the primary group ‘discharge’. In ShiftCliq we could see exactly which component was involved – a valve – and how the problem was affecting production costs, whilst SAP told us its impact upon maintenance costs. Looking at the issue in more depth, we realized not only that the valve was wearing out fast but also that the replacement units were not always being fitted correctly. Using ShiftCliq we were able to ascertain almost immediately that the new valves had been installed and configured by different people. At first it was thought that the rapid wear was due to a construction problem, but analysis showed that the valve was incorrectly positioned. From ShiftCliq we could tell that it needed repeated cleaning because it was too close to the pump. By relocating it and from then on using units preassembled by specialists, the problem was solved and we saved €50,000 a year.” A quick calculation shows that figure was arrived at…
The valve was changed eight times in the two months prior to the modification, compared with just once in the first two months afterwards.
- 5 (number of cement silos at the plant) x 7 valves = 35 valves per two months x 6 = 210 valves per year.
- 210 valves x €300 (servicing cost per valve) gives a total theoretical saving of up to €63,000 and an actual saving of €50,000.
Digital logbook saves hours looking for reset button
At ENCI, a burner dries incoming blast-furnace slag from the adjacent Tata Steel plant. “Two years ago a safety cutout kicked in,” recalls Hoogervorst. “The system was overpressurized and switched itself off, so that it had to be reset. It took our people six hours just to find the right button. The same thing had happened years earlier, and was of course registered in the paper log at the time, but that made the information virtually impossible to find. Now, with the digital logbook, you simply type in the location – in this case “combustion chamber” (BK3610) – and everything just appears. The application displays the full history of all components, including the location of the reset button. The great thing about this system is that the longer you use it, the more information you have in the database. Information you actually need on a daily basis, which saves you time and money.”
SAP is a maintenance system and so by no means reveals everything about a disturbance. Before a failure actually occurs and is recorded in SAP, a lot has already happened. “In ShiftCliq, for example,” Hoogervorst says, “as well as seeing that a pump has been replaced, we might be told that it had not been working properly for some time and that after the failure three men spent four hours cleaning it. That is useful information to know if the disturbance recurs.” OEE Toolkit records the frequencies and times of disturbances, and which shift was on duty when the problems arose. “With all this data we can very quickly identify bottlenecks, and not only solve countless problems fast and efficiently but also improve processes step by step at the fundamental level. Making the most of your systems delivers huge benefits.”