With its "˜make today, sell tomorrow' scheduling, the food and beverage manufacturing sector has an almost total intolerance to production breakdowns. They have developed sophisticated techniques to keep the lines working and the distribution channels full. Guy Kennett of Mitsubishi Electric explains that other sectors can benefit by adopting similar systems.
Local food and beverage companies have always had a focus on the freshness of their products. In recent years this has increased markedly, due to tightening regulations and rising consumer awareness. This has led, naturally, to a focus on efficient production and distribution, with products typically being delivered to the consumers within 24-48h of manufacture.
Producers of frozen, tinned and dried food are under the same pressure because they supply through the same distribution channels, so have exact dispatch time slots to meet. Further pressure is then brought to bear by the major supermarkets, which insist on precise and timely deliveries so that their stockholding is kept to a minimum.
This reflects through to the production floor with a need for close to perfect reliability of manufacturing lines and machines. Fortunately, many of today's industrial components - motors, gearboxes, controllers, conveyors, sensors, etc. are very, very reliable.
However, "˜components' are always used in "˜systems', and the reliability of the system is compounded from the reliability of each component. For instance, a system consisting of 10 components each with a reliability of 99 per cent would have a reliability of about 90 per cent, while a system with 20 components would have a reliability of 80 per cent. If the reliability were only 95 per cent, a 10-component system would be about 60 per cent reliable, and a 20-component system 36 per cent.
Additionally, component failure is far from the only cause of machine problems. The wrong raw materials could be used, a badly driven forklift could cause damage, a power outage, water leak or many other problems could slow or stop production.
Therefore, production engineers in food plants fully appreciate the value of top-quality equipment, and they also understand the need for first-class support and service contracts.
We can draw an analogy with motoring: if you do not drive much and have backups in the form of public transport or helpful neighbours, then you have the option of buying a cheap second-hand car and worrying about breakdowns when they arise. If things are a bit more critical for you with school runs, commutes to work and out-of-town shopping, then you would probably want something more reliable - probably a car less than five years old. If driving is critical to you, perhaps because your job requires you to travel 20,000 miles a year or you have to respond to emergency call-outs, then a brand new car from a quality manufacturer is probably the best option.
But when you buy a brand new top-of-the-range car, you don't just get the vehicle, you automatically get an assistance package too. This includes breakdown cover, and - more importantly - first-class servicing. In fact, your dealer will log your service reports and thereby be able to take proactive care of your car, for example by replacing wear components before they start causing trouble, or by checking the engine management log for signs of developing problems.
However, there is a weakness in this analogy: a production plant evolves over time, rather than being a discrete item like a car. Therefore, production engineers need to add a few more steps to ensure plant reliability. These are basically common sense: listing all the equipment, assessing its reliability and making sure there are robust backup plans in place. However, this is almost invariably easier said than done - and few production engineers would ever be able to make enough time to see such a project through.
Fortunately, Mitsubishi Electric has developed their Diamond Service Contracts from within the System Service Programme that takes all these issues in hand and offers plant operators peace of mind. Diamond Service Contracts are flexible and can be adapted for any situation, large, small, complex or simple. Contracts defined in one, two or three Diamond service levels and are tailored to meet the customer's needs.
The first step is an audit of all the hardware in the production system. Each component needs to be listed, given an individual reference number and have its age and service record logged.
This is followed by a software audit, which should include any modifications, patches or fixes. It is likely that the software will include multiple vendors and different versions of some programs. However, the important thing is to do a regular total software backup, so that if something goes wrong, there is a defined recovery point.
With these initial steps in place, Mitsubishi will start developing a risk reduction strategy. It identifies those parts of the production system most likely to fail and those parts where failure will be most devastating, and highlights them for early improvement. In the case of hardware, this often means replacing aging components. With software, the library of software backups and version control is vital in a disaster recovery situation.
Mitsubishi are able to offer "˜multi-vendor' service contracts, which allows the end user to place one service contract to deal with all of their installed automation equipment, regardless of manufacturer. This sets Mitsubishi apart from other automation equipment vendors, who are normally only interested in their own brand components.
Another vital element of a robust service contract is to have response strategies in place, ready to be implemented in the case of breakdown or other emergency. This probably includes developing standby procedures that will keep production flowing, plus support from Mitsubishi's System Service Programme in the form of 24-hour telephone support, online support and service engineers travelling to the site within a previously agreed response time.
A "˜spares' strategy would include having on-site spares for critical components, fully maintained and with site engineers trained on their operation and installation.
As stated earlier, much of this seems to be straightforward and obvious, but actually implementing it in the "˜real world' is always far harder than expected. Therefore experience counts for a lot, especially in breakdown situations. For instance, it is natural that there will be more problems at night and over the weekend when there are fewer staff on-site, and experience shows that often the night shift may have different names for various pieces of equipment than those used by the day staff. Therefore, it is a good idea to give machines, systems and components reference numbers rather than names.
Another common issue is that maintenance logs are not kept up to date or are left incomplete. It is therefore good practice to set up a system that raises an alarm when log data is overdue or missing.
Mitsubishi Electric Diamond Service Contracts have been used in the food and beverage industry for many years and also in other time-critical sectors such as water treatment, traffic and transit, etc. In recent years, more and more sectors have come to realise their benefits and are adopting (and adapting) them.
One final thought to close with: the cost of a 12-month service contract is probably equal to a very small number of hours' stoppage. The cost is designed to make the option of effectively insuring the system one that is an easy decision to both make and justify.
To find out more about Mitsubishi Diamond Service Contracts please visit automation.mitsubishielectric.co.uk.