Right place, right time right condition

Factory efficiency and product quality are both highly susceptible to disruption if crucial assets of all types – plant and machinery, but also people and inventory – aren’t available when they’re needed. So effective asset management and maintenance techniques will keep customers happy and production lines purring along. But they have much more potential than that: they lay a solid foundation upon which successful lean manufacturing initiatives can be built to drive out waste and cost and improve agility. As a first step, understanding where to expend the effort is absolutely fundamental to any asset management initiative. Although the procedures for identifying the assets that have the biggest impact on the business will vary according to the type of manufacturer, something likely to be common to everyone is – there will be surprises. Today’s enlightened view is that maintenance resources should be concentrated on assets and their associated tools and equipment that are critical to meeting production demands. Thus tools and resources used on production bottlenecks are the ones that should receive most attention, while attention to other equipment is a secondary consideration. But this thought alone can meet resistance, as it contradicts the traditional view that if you have an asset you should make sure it works. But as Hugh Williams, managing director of consultancy Hughenden points out: “Lean manufacturing has over a long period come to terms with the fact that just because a machine isn’t producing something that doesn’t mean it’s idle and wasted.” Either way, identifying exactly which assets are the most critical is itself often far from trivial. Most of us understand that a bottleneck is where we’re essentially stuck for capacity, but it’s easy to fall into the trap of pointing out a machine that’s complicated to manage, difficult to set up, or that breaks down frequently. Is that the bottleneck? Or is process improvement called for? And to add to the complexity, in some factories the bottleneck moves, particularly if there are changes to the product mix – and in a job shop, where the mix can change dramatically, it can move quite a lot. Once bottlenecks have been identified, however, the next step is to put in place a maintenance plan that’s optimised based on criticality. Once again, expect resistance, as engineers are understandably bound initially to target assets that have suffered the biggest downtime, or are the most challenging. BAe Systems made the transition by ensuring that, once the highest priority assets had been identified, they were labelled using a straightforward system of specifying criticality standards for everything associated with them – in its case, the tools, systems, equipment and assembly jigs that are ultimately used in manufacture and test of military aircraft. Keith Hartley, team leader within the asset management team, explains: “We’ve actually tagged tools to one of three criticality standards. We have service level agreements in place for calibration and maintenance that vary depending on the criticality standard. So if something in category 1 requires calibration, the calibration authority will automatically give it priority over everything else.” In addition, scheduled calibration and maintenance activities are planned around production schedules to yield maximum productivity potential. Simplicity and clarity, and a holistic approach. And the value goes further: as a result of the criticality assessments some tools have been duplicated, but others have been mothballed or scrapped. Proactive tracking In fact, BAe Systems now uses a modified Datastream MP5 maintenance management system to track all its asset utilisation. “We may have six identical items that we usually send from stores for calibration every three months,” says Steve Frost, tooling logistics manager. “By tracking utilisation we might discover that only three are out at any one time, so we can withdraw three from service and save on wasted calibration costs.” And the firm now records and plans servicing and calibration activities, and uses the system to work with production planners and the calibration authorities. The result: Frost’s department lives up to its motto – ‘right tool, right place, right time, right condition’. Moving on to maintenance itself, fact is that for most of us, unplanned downtime and maintenance on critical assets have a significant impact on availability. Clearly, targeting maintenance resources on such plant and equipment is a start, with maintenance crews primed to give them priority. But additional preparation might include the holding of critical spares on site, and don’t rule out rehearsal for certain jobs. “On the principle that every minute you lose on that machine are sales you will never get back again, every second is critical,” insists Williams. “Maintenance should be planned and rehearsed to the minute – just like a pit stop on a Formula One car.” That said, different categories of asset require different maintenance strategies and, as usual, it comes down to compromise – with cost-benefit being the key factor. Traditional preventative maintenance is usually taken for granted, but can be expensive. Using techniques like condition monitoring opens the door to predictive maintenance which, although not necessarily cheap to set up, can be very cost-effective, particularly in terms of machine availability in the long term. But for some equipment, a third strategy – also the cheapest – might be simply to run to failure. If something isn’t going to significantly impact the business while it’s out of action for a time, it can make sense just to wait for it to go wrong – again, allowing maintenance resources to be concentrated on the critical bottlenecks. Whatever you use, when it comes to unplanned maintenance, Ian Thompson, commercial manager at Wolfson Maintenance, suggests that even when the problem is fixed, that shouldn’t be the end of the story, especially if it’s a bottleneck resource. “You don’t just want to complete the job, but also understand why the item failed, so you can start looking for the root cause, and implement a loop of continuous improvement.” But if in spite of everything, a failure keeps recurring, that might be a hint to adopt the fourth maintenance strategy – to design out the cause. Putting all this together, asset management for agile manufacturing means having the right machines working at the right time, and while good processes and IT are key, Joy Bulcock, consultant with the Industry Division of ABB, adds: “The thing that makes it happen is people talking to each other.” Communication and the availability of right human resources are just as important as the right equipment in working order. One metal box manufacturer was able to boost productivity by increasing what were determined to be key skills by 38% over a period of several months. The trick there was to start a programme of cross-skilling, with team leaders knowing that training was essential to meeting their productivity targets.