Last Updated: 31 Aug 2010


Activity: Manufacture of electronic devices and components

Task: Low-cost, high-volume production using a wide range of production technologies

Complexity: Medium

Size: 850 employees Outstanding Features: Automation, component replenishment, cell design and operation

Mass production is the name of the game at Honeywell's Motherwell factory. A manufacturing unit serving several different sales and marketing businesses, the plant produces many of the thermostats, controllers and switches for which the Minneapolis-based company is well known. Among customers for these products are the likes of Boeing, Bosch, Electrolux and Rolls Royce. But the list also includes the innumerable builders' merchants and electrical wholesalers who ensure that a huge proportion of homes, offices and factories have a Honeywell product in them somewhere.

The Motherwell factory is a big one. It covers over 500,000 square feet and encompasses an extensive range of manufacturing technologies. The judges were impressed by the plastic injection moulding facility where robots, supported by fast component changeovers and in-line statistical process control, feed the rest of the plant with parts on a just-in-time basis. Die changes, which once took six hours to complete, now occupy just nine minutes.

But it is at mass-production assembly that the plant really excels. One particular microswitch is produced at a rate of over 20 million a year. The line in question is one of the slickest examples of fast and tight assembly automation that the judges have seen. Hoppers of tiny components are poured into bins at the prompting of flashing 'fill me' lights, but that is just about the limit of human involvement. The line works four shifts, around the clock, with computer-based statistical process control providing a wealth of monitoring and control information.

'Our skill lies in knowing how to automate the manufacturing process while achieving the right degree of precision,' says director of manufacturing John McDougall.

But while the assembling of small components is often totally automated, some 95% of assembly work in the factory is carried out in cells. Larger and more complex products, such as room heating controllers, are generally assembled in U-shaped cells which Honeywell calls 'rotating cells'. An unusual feature of these is that they do not require a full complement of people in order to function effectively. Operatives work on batches of five at each station, and will follow a batch around the cell, if necessary, until the assemblies are complete. Even best-selling products, such as the ST699 programmable controller, are put together in this fashion. The cells may operate with half-a-dozen people or with only two or three, according to the state of demand.

Raw materials and component stocks are increasingly held within the cells rather than in a central stocking point, which effectively turns the cells into mini-factories. Component supply to the cells is well-organised and smoothly efficient. 'Kanban trolleys' with enough parts for a couple of hours or so are replenished every 30 minutes. The two hours is dictated by replenishment policy. 'We top up with full boxes only,' explains McDougall. 'Counting is inefficient - and a waste of time.' Although Motherwell has been an MRP II Class A site for over 10 years, current thinking at the plant is moving away from this technique, McDougall explains. Electronic data interchange and faxed kanban cards (known as 'faxbans') are currently the preferred means of transmitting requirements to suppliers. A van calls on every supplier within a 40-mile radius daily, picking up that day's components and raw materials which it delivers direct to the appropriate production cell.

Under this system, invoices have been eliminated. 'Once a week we tell our suppliers what we think we've received, and every fourth week we send them the money,' says McDougall. Inspectors, goods inwards personnel, procurement and planning people - all these have been redeployed. They are now engaged in the manufacture of products rather than the shuffling of paper.

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