Testing, testing, one, two, three

Simulation has always been seen as difficult and expensive, requiring powerful workstation hardware, costly software licences and skilled simulation engineers to run it all. Thus, although the business benefits could be substantial, it was only a practical proposition for larger companies, and usually only for their major exercises, such as introducing a new product or process. All that is changing – and this is very good news. The benefits themselves should by now be well understood: MCS has carried many stories of unnecessary cost avoidance on production equipment, factory layout changes and even warehouses. But the point here is that the advent of more intelligent software that runs on everyday PCs, at a significantly lower cost, and can be driven by the very people that need it, is triggering a transformation in how we can think about simulation. The goals remain unchanged. "Simulating the impact of change is the easiest way to minimise the risk, or measure the impact of the change. It can help you understand where to make change, and who's affected by it," observes John Gooday, commercial manager for software at controls and MES (manufacturing execution systems) developer Rockwell Automation. It's worth pointing out that minimising risk means that not every application of simulation will result in headline savings, so ROI (return on investment) calculations can be problematic. As Bob Lloyd, business development manager for engineering consultancy AMTRI, puts it: "How do you make a financial case for not making a mistake you haven't made yet? You can't see it on the bottom line. It only shows up when you've made a mistake – and then it's too late. We've had jobs where we've been able to say to customers, 'If you do that, it won't work – you won't meet the cycle times,' or whatever." Nevertheless, risk avoidance can mean very big money saving, as USA conveyor manufacturer Span Tech found when introducing a new handling system for a frozen pancake maker. Span Tech designed the new system, but had tight productivity goals to meet, so it needed to check it would be successful before embarking on the project. Using Rockwell's Software Arena simulation tool, Span Tech engineers were able to spot problems and modify the design before committing. "Developing the simulation saved considerable time during installation, start-up and debugging," says Leo Schroeder, president of Span Tech. "The start-up phase took us three to four weeks, but it could have taken us three to four months if Arena hadn't already provided a solid solution." Automotive OEM Swindon Pressings (see panel over page) also used simulation to avoid unnecessary capital expenditure at a time of change. Its story illustrates how simulation systems can also achieve considerable savings through optimising existing procedures – with the company cutting costs of potentially £57,000 annually by smartening up on machine die changes. But crucially, Swindon's story also highlights a major change taking place in simulation today. Traditionally, a simulation engineer would have to build a computer model from scratch. It could take Peter Jones, for example, the simulation engineer at Swindon Pressings, up to three months to model an assembly area. But now, with reusable library models in simulation specialist Tecnomatix's eM-Plant software, that time is slashed: "I can do it in about three days," he says. Jones had to invest in creating library objects that he can re-use, but it means he can now create new models with minimum effort. Model libraries Simulation software vendors are also working hard here, providing useful models and components that accurately reflect real-world devices. As Rockwell's Gooday explains: "We are building standard libraries of devices, such as robots and conveyors, and resources, such as people and lorries." And the result: there are versions of its systems for packaging analysis that include packaging machines, fork lifts, palletisers and other devices. Conveyor supplier FlexLink Automation has adopted the approach, plumping for Visual Components' 3DRealize simulation tool, and building library models for its range of conveyors and other products. A key benefit of this simulation environment is parameter-driven models, which reduce the work necessary to build up the library. As Kosti Karppinen, software development manager at FlexLink, explains: "We have built a library of all our models [but] we only need one conveyor model and you change the parameters, rather than have lots of different versions." Another very important change is that simulation models themselves are getting easier to use. In the past, once simulation engineers had built the model, they would also be needed to operate it – to run the 'what-ifs' etc. Now, simulations on some systems can be run by users themselves – production engineers, or whoever is relevant. Swindon Pressings isn't doing that quite yet: "We have considered setting up models so other people can use them," says Jones. "Although it's not something we do yet, it means they could use the cheaper run-time software licence. But we'd have to give the model a better user interface." But this is an approach at FlexLink. "Our vision has always been that simulation tools need to be so user-friendly that engineers who understand production can use them. After all, simulation engineers are not production specialists," says Karppinen. "Now we don't need simulation engineers. In fact, we have implemented simulation in such an easy way that even the sales guy can use it." That is a seriously big development. It means that, whereas previously most smaller organisations had to turn to specialist consultancies (even Span Tech used Simulation Modelling Services), now they might not. FlexLink's Karppinen's says: "Our customers have seen how we use [the 3Drealize software] and they have bought it for their own use, because they don't need to pay simulation engineers any more." FlexLink designs the layout and builds the model – the manufacturer still needs to employ a consultancy, or employ a simulation engineer, for that – but then the customer takes over. "Now, they can run different products and make other changes, like different packaging cycle times, and the simulation tool can tell them they need more machines or operators." What does it add up to? Coupled with reducing software costs – and 3DRealize seems cheaper than many other simulation offerings – these changes mean that valuable simulation is at last within reach of SME manufacturers. And the importance of that cannot be exaggerated. As AMTRI's Lloyd says: "The smaller you are, the more crucial simulation is. One mistake can put you out of business." "Previously, only the biggest customers could ask us to do simulation for them – the cost could be between eur5,000 and eur20,000 and would take days," explains Karppinen. "Now it costs much less and takes a matter of hours. I have seen companies of less than 10 people make good use of 3DRealize." A final thought: Swindon Pressings' Jones points out that, beyond simulation's headline benefits, is its ability to find the gaps. "On a large project that spans different departments, simulation very often finds the cracks in the process," he says. "In order to get the model to work you have to talk to all the people, and you soon find out where something has been overlooked and one part of the process doesn't quite tie up with another. If you have simulated beforehand, this gets resolved before switch-on."