Shop floor integration means riches at Princes

Studies of so-called 'shopfloor to top floor' connection have shown many times the benefits, once information starts flowing from the plant into the ERP system – and vice versa. And they're real: at Princes Soft Drinks, for example, results include reduced operating costs, a cut in warehouse stock and minimised re-mixing costs. But at Princes, as elsewhere, the secret of success has been knowing exactly what on the shopfloor should be integrated to the ERP system. Because unless there's an unlimited IT budget, it just isn't going to be cost-effective to connect anything like every PLC data point or smart sensor in the factory to your business system: and there won't be the return on investment. This is not about wholesale integration. It's a difficult challenge, because one of the main benefits of shopfloor to top floor connectivity is that it provides visibility. And that visibility helps understanding – and specifically helps to identify problems and refine solutions. Everyone can relate to the truism that if you knew what the problems were, perhaps you wouldn't need the project. Of course, there are instances where you do know what the problems are. John Gooday, commercial manager for software at manufacturing execution system (MES) provider Rockwell Automation, cites the example of a materials handling company based in South Wales. "The entire manufacturing facility is reliant on a bottleneck of two cranes," he observes. "If they are out of operation it stops the whole production, and that's what was happening. They were going into alarm, and stopping production." But without visibility at the top floor of the detail of these alarms, no one could spot the trends and identify the causes, much less suggest solutions. "The person operating the crane would just solve his problem, but wouldn't have the overall view. So no one had the overall picture to know that a sensor was breaking so many times a day, for example," says Gooday. However, once integration was in place and the data was fed back to a management level, the big picture that emerged from aggregated data spurred management into action. It provided them with enough information to make good decisions. Getting it right Much the same was happening at soft drinks giant Calypso, unitl it introduced MVI's Eventsengine MES. Now, half-known machine and process problems are being dealt with as the system, first, identifies them, and second, quantifies them. "Until then, something might have happened numerous times in a shift but never been recorded," says Denver Higgins, production co-ordinator. "The operators knew there was a problem but couldn't convince anybody to get it fixed." Eventsengine runs via a thin client and web browser, with production office screens and links into machine PLCs and sensors, as well as to Calypso's Geac System 21 ERP. There's a touch screen on each of the lines, which also provides works order information, and operators are now forced to enter reasons for downtime by pressing pre-coded buttons. They can also key other explanations, and the buttons change as problems are resolved and new ones come to light. Problems uncovered? Holmes refers to a robot that was dropping cups. "Eventsengine allowed us to quantify the problem [which] turned out to be an air line." An end of shift clean now means a controlled 10-minute stop rather than unscheduled stops throughout the production shift – and no more waste. "We also had a cutting tool that was leaking nitrogen and the operators kept topping it up." As it escalated, the system picked it up "and we found there was a leaking seal. The engineers fixed it – end of downtime." Conventional wisdom might dictate that you start by identifying problems, and only then connect what you need to in order to solve them. Catch 22. But by being educated about the technology, it's possible to identify areas for potential improvement that wouldn't necessarily be highlighted as currently causing problems. For example, a manual paper-based communication from the shopfloor may work adequately, but if it was faster, cheaper and more accurate, there would be greater scope for analysis by management. Princely solutions Indeed, reduction of paperwork was one of the motivating factors at Princes Soft Drinks, which initially saw the connection of its PLCs into the SAP ERP system as a means of cutting down on time and effort. And that was a big deal: Princes is the third largest soft drinks manufacturer in the UK, number one in squashes and second in juices. It's is a demanding manufacturing environment, with three-shift operation of a fast batch-making production facility. "Initially, we thought we would remove the increased burden that ERP had visited on us of recording transactions," explains Neil Crew, group IT director at Princes. "In many ways ERP made life worse for the factory people. We were using it to track things like internal movements much more closely, but the effect at the sharp end, for the operatives to have to record transactions, was too much." From those beginnings, the project expanded to consider wider benefits. "We spent quite a bit of time in advance of the implementation working with various departments to understand what benefits we might expect," explains Crew. "We included the finance department in that, and got them involved in the process throughout." Ultimately, the project expanded to two stages over four years, and ended up with the adoption of a Siemens Simatic IT MES integration infrastructure. Crucial to its financial success was the requirement to only connect up what made sense. "As a least-cost manufacturer, one of the tricks for us was trying to understand where to make that balance," continues Crew. "We are not required to track every single thing; we have come at it the other way. We make low-margin products and we know where the big issues are. We are just trying to drive product through the factory as quickly and effectively as we can, and are interested in greater visibility in those spots where we need to have better control of what's happening." For Princes, these are in the areas of raw material usage at the beginning of the production process, and the finished goods coming off the end of the lines. "Some of the areas in the middle, such as line productivity, just aren't an issue. We don't have to do much tracking, and you'd soon know if something went wrong – if you weren't putting caps on the bottles, for example!" Benefits achieved at the plant include a reduction in the raw material inventory by providing more accurate data relating to materials used and reporting this information in real time. Operating costs have also been reduced as manual data entry has been replaced by direct communication between SAP and the Siemens MES. Moreover, re-mixing costs have been minimised, as electronic collection of information for all batches reduces the incidence of operator errors. Scrap and re-work have thus been reduced, he reports. Expedited deliveries to customers have also been minimised, and electronic recording of all information on all batches now provides comprehensive reports on each batch automatically, without time wasted in collecting data. In fact, one manual weekly audit has been eliminated altogether. The right mix As an example of benefits found by monitoring the batch mixing process: before, with three-shift operation and paper-based recipes, people were running subtly different processes. Crew: "For example, a recipe might call for 23kg of a raw material that comes in 25kg bags – but one operative might decide to put the whole bag in, a decision that could well make sense. However, everyone else expects there to be 23kg so the laboratory would throw it out on inspection, and the batch would have to be re-mixed with more liquid." Without a holistic view of what was happening, nothing changed: but with shopfloor visibility of materials consumption uploaded automatically to the ERP system, such issues are now quickly spotted. "You can either insist on 23kg or change the recipe to 25kg – it may not matter, but at least you've found the problem," says Crew. At the opposite end of the process, having visibility of finished goods speeds end-of-line clearance, with the number of bottles produced being uploaded automatically to the SAP system. "As soon as you have represented the fact that you have finished products in your ERP system you can move the goods off-site quickly, or deliver to the customer," says Crew. "Otherwise, you have a pallet hanging around until it's been properly confirmed: move it off site too quickly and you'd risk losing track of what's happening." Although the Simatic system does also drive transactions through the business – by transmitting daily production plans, recipes and other information to the shopfloor – Crew says that isn't where the true financial value lies. "It offers a fascinating view of what's happening in your business and that has always been the real benefit."