Mind the gap

Too many manufacturers are held back by a gap in their IT systems, but it's not the gap that they probably imagine. And the result is missed opportunities, says Paul Lane, sales director at specialist manufacturing software vendor Seiki Systems. Specifically, he explains, opportunities to boost capacity utilisation, opportunities to improve due date performance and opportunities to reduce work-in-progress. "Twenty years ago, people used to be talking about the gap between CAD and CAM systems," he says. "Now, it's the gap between ERP and manufacturing execution systems that is of concern. And, ironically, although it's a gap that causes more difficulties for manufacturers than the gap between CAD systems and CAM systems, not enough businesses are aware of it, let alone doing anything about it." ERP, explains Lane, follows the familiar logic of MRP. In short, take the order book – forecast and actual – 'net off' finished goods inventory on hand and back-schedule by the relevant applicable due dates. The result is the factory's workload, together with the due dates that it must meet. Which is precisely the problem, says Lane: ERP tells the factory what to do, but not how to do it. Here, management teams are often on their own, relying on gut feel, spreadsheets, rudimentary planning boards, or manufacturing execution systems. The plan?is little more than a wish-list "ERP gives them the due dates, but it doesn't normally take into account the capacity and scheduling limitations that the business faces," he points out. "The 'plan', as ERP sees it, is little more than a wish-list rather than a reflection of what the business can actually achieve." And the inevitable result is missed order delivery dates, poor machine utilisation as planners chop and change equipment setups in order to keep customers happy and excessive plant-floor overtime as harassed production managers struggle to catch up. But there is, of course, a better way: Advanced planning and scheduling (APS) systems. And Seiki, of course, is one of the small number of vendors supplying manufacturers with such systems, through its real-time Seiki Scheduler. Simply put, APS systems do what ERP systems don't do. They produce achievable schedules, based on real-life factory constraints – constraints such as people, machine capacities, tooling, and material availability – and which provide a platform from which to deliver manufacturing performance improvements as well as on-time orders. "One option is to offer customers realistic due dates based on finite capacity planning, with the schedule optimised to meet your own goals and objectives – improved utilisation through fewer setups, work-in-progress minimisation, or better schedule compliance," says Lane. "Or alternatively, you might want to take another tack: Here are the dates that our customers would like us to meet: Now, what do we have to do in order to meet those dates? Through 'what if' simulations, you can see exactly what is required by way of additional overtime or extra capacity." And the starting point, in both cases, is a link between the manufacturing execution system and the ERP system in the form of an APS system, closing the gap that presently exists between the two. In short, says Lane, a manufacturer will have a link going from ERP to the manufacturing execution system providing details of the dates that customers want their orders delivered and a link going in the other direction, back to the ERP system, providing 'as-planned' due dates scheduled by the APS system. And for factory-floor personnel, the power of this real-time, two-way link is amplified when the APS system isn't dealing with dry numbers and dates, but instead provides a planning interface containing rich visual management tools, easily mastered by shop floor management. "APS at its best isn't simply presenting management with answers, but instead is providing them with a tool set to explore those answers themselves – carrying out 'what if' analyses to identify the impact of making schedule changes to meet new customer requirements, for instance," says Lane. "By visually 'dragging and dropping' orders around in the schedule, they can see for themselves the impact – not just on which other orders might be affected, but also on measures such as due-date compliance, work-in-progress and latterly the ultimate impact on overall equipment effectiveness." It is, in short, a compelling vista and one which many manufacturers will regard enviously. "The bottom line is that on its own, ERP doesn't deliver and neither do manufacturing execution systems," sums up Lane. "You have to bridge the gap between the two."