Lean, green and watching the machines

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by Kip Hanson

The Problem: Understanding machine efficiency

The Solution: Machine monitoring software

Ontario aerospace shop implements machine tool monitoring system

In 1975, Drago Cajic left his job in the machining trade to open the doors of Koss Machine and Tool Co. in Mississauga. From the very beginning, he focused his efforts on the aerospace market, and quickly earned a reputation for quality parts and on-time delivery.

Cajic started out with a Colchester engine lathe and a handful of other equipment, but it wasn’t long before the first CNC machines arrived. Since then, Koss’s shop floor has grown to 3,700 sq m (40,000 sq ft) and is filled with dozens of machining centres and lathes.

In the early 90s, Cajic joined with Brampton Processing, a metals finishing company specializing in plating, painting, and non-destructive testing of aerospace parts. Together with its in-house assembly capabilities, the move made Koss a one-stop shop for wing spars and ribs, bulkheads, floor and cross beams, seat tracks, and landing gear components for aircraft programs across all of the major players in the industry, including Boeing, Airbus, and Bombardier.

To signify its level of vertical integration, the company changed its name to Koss Aerospace. Vice president David Cajic says Koss’s 85 employees are committed to operational excellence in aerospace manufacturing. Beginning in 2009, they embraced Lean methodologies, and through a process of continuous improvement, cellular manufacturing, and an eye towards process flow, now boast quality levels of 99.5 per cent. Likewise, green initiatives such as reusable containers and a newly installed chip management system help improve Koss’s bottom line while reducing environmental impact.

The company’s most recent improvement efforts–and quite possibly its most promising–centre on machine monitoring. Like many shops, Koss’s equipment utilization is a fuzzy figure, one that management makes assumptions about but doesn’t really know. Rather than continue guessing, Cajic took steps to understand this most important of metrics: how many hours each day do the spindles turn?

It’s not the first time the question has come up. Six years ago, Cajic and the Koss team purchased tools for machine monitoring, but soon learned they’d wasted their time. “It was a big fail,” says Cajic. “We were the guinea pigs for software that was never proven or tested, and ended up returning it. The whole thing left us with a sour taste in our mouths.”

Since then, the company has grown. In fact, over six million dollars has been invested in equipment and infrastructure in recent years, and Koss management knew they couldn’t optimize machining operations without some way to measure efficiency. David Cajic took another hard look at monitoring software.

“We shopped around, but in the end decided to partner with Memex,” he says. “They provided us with some great customer references, and delivered an implementation plan customized to our machines. Based on our last experience, this gave them a lot of credibility.”

Memex Automation, Burlington, ON, presented Koss Aerospace with its suite of Manufacturing Execution System (MES) products. Chief among these is its Merlin OEE (Overall Equipment Effectiveness) system, which enables users to monitor machine status in real time, and capture data such as stoppage reasons, error codes, spindle and feedrate overrides, and even work order information. This data can be imported to the customer’s Enterprise Resource Planning (ERP) software and used for dashboards and reports, allowing management to rack and analyzse the efficiency levels of operators and equipment alike.

Memex product engineer Randy McDonald says much of this information is pulled from the machine automatically. “Feed hold, cycle interruptions, alarm states, optional stop condition–everything is captured. And in those instances where operator input is needed–say he or she stops the machine to check a tool­–then a window pops up asking for a reason. All they have to do is pick the right code, or scan it with a barcode reader.”

McDonald says operators quickly learn this is a tool that eliminates second-guessing. “If they have a maintenance issue during the week, nobody’s going to come to them on Friday and say, ‘why were you down for an hour on Tuesday?’ They don’t need to remember they were in an HR meeting, or that the chip conveyor backed up. It’s all recorded in a database, using real numbers.”

Databases are a manufacturer’s best defense against inefficiency. Unexpected downtime can trigger an email to a supervisor, repeat problems can be understood and dealt with promptly. To Koss, this means no more guessing games. “Merlin makes everything straightforward,” Cajic says. “Everyone can clearly see what areas are doing well, which ones need improvement, and who’s doing poorly. It all becomes very black and white.”

Koss isn’t done with the implementation. The initial launch started a few months ago and was restricted to a handful of machines, among them a Mazak Variaxis 630-5X II five axis machining cell equipped with a Palltech automated material handling system. The team plans to expand the rollout soon to a pair of SNK five axis profiling mills, a Niigata horizontal, machining centres, several large CNC lathes, and a new HBZ compact high speed machining centre from Handtmann.

These two SNK five axis profiling mills will soon be monitored as Koss rolls out the machine monitoring software on all its machines.Installing an OEE system requires effort and planning. Merlin has a number of dashboards that displays information to all levels of the company, as well as the option to present data to the shop floor on large computer screens. Multiple production reports can be customized and scheduled for automatic
email distribution. Many companies may choose to develop their own custom software tools, as well as integrate production information directly to an ERP system. Merlin supports these initiatives with various connectors and report writing capabilities, something that Koss is busy exploring. Despite this, Cajic says the initial results look good.

The Merlin system will be rolled out on other machines in the plant, including this Handtmann.“We’re already achieving better visibility,” he says. “Because the operators can’t run without inputting downtime codes, nobody can override or get around the system. If for whatever reason they’re not as efficient as the person next to them—maybe there’s a tooling issue or a programming problem, we’re able to capture that. Merlin highlights the bottlenecks, and alerts the supervisor when there’s a problem. So even though we’re just getting rolling on this, we already have greater efficiency where the monitoring is in place.”

He adds that “a lot of companies aren’t totally aware of all that happens on the shop floor. They think they’re doing better than they really are. But when you actually sit down with some real data, and can do some analysis, you generally find there’s more waste than originally thought.

“Based on that, we expect that the benefits of the new system will be great. We’re very excited.” SMT

Kip Hanson is a contributing [email protected]

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