Weighing at the speed of lights

Weighing is seldom ‘front of mind’ unless it is accompanied by an angry morning stare at the bathroom scales. It is, however, one of the most fundamental metrics at the core of manufacturing processes; particularly in the packaged food and fresh produce sectors.

With escalating costs and downward pressure on product prices, growers are continually on the lookout for simple ways to increase productivity. The table grape industry relies on manual packing processes, often utilising casual labour to pack into punnets/boxes/bags ready for supermarket consumers. Labour is typically the biggest cost to a business, but there is another that can go unmeasured - the cost of extra produce given away in overfilled packs. This can add up to thousands of dollars per week if unchecked.

An emerging trend among strawberry growers in south-east Queensland has shown how looking at weights in a different light (or lights, in this case) can lead to substantial savings. Rather than focusing on a numeric weight display, packers have utilised traffic light signals on their packing scales to improve product yields with some staggering results. Other fresh produce sectors and manual packing operations can apply the same improvement and reduce giveaway to potentially achieve considerable gains.

This simple idea has two immediate benefits - reducing overfilled packs and increasing packer speeds. People respond to signals with far less thought process than looking at numbers. Green means ‘go’; red means ‘stop’. It is part of everyday life, transcending language and cultural communication barriers.

By utilising packing scales that have a target-based signal system, packing staff and management alike enjoy immediate benefits, and stringent fill targets can be set for both upper and lower weight bands. Packing staff are able to quickly fill and check that products are correct, and the increased visibility of red/green lights means management can easily oversee performance.

Braetop Berries near Queensland’s Glasshouse Mountains were staggered to find that rechecking several cartons of traditionally packed punnets produced several extra punnets of fruit when using traffic light scales. This was “money in the bank” according to father and son team Peter and Aiden Young.

Terence Roy, a berry farmer from Coolhaven Farms, cites improved packing speed as another instant benefit. “Our packers work more efficiently since using the light signals on our new A&D Australasia scales - it’s made significant improvements to our productivity in both speed and reduced rework of out-of-spec punnets,” Roy said.

Last year Berry Sweet Farms, one of Western Australia’s largest strawberry producers, replaced regular scales with scales with built-in LEDs, prompting packers when correct weights were reached. Owner Anthony Yewers says he has not looked back since.

“Preventing underweight punnets is essential to our business and customers, but reducing extra giveaway is a no-brainer,” Yewers said. “Using traffic light signals in our packing scales has put a big tick in both these boxes.”

While the above examples are from the berry industry, the ‘packing by lights’ principle is valid for any manual packing process where weight targets are set. With supermarkets pushing for more pre-packed fresh produce in Australia to reduce their own wastage and occupational health and safety risks caused by slippage on dropped grapes, there is a growing move towards table grape pre-packs in both bags and punnets. In this case the traffic light technology could be expected to have similar gains to those seen in the berry industry.

But the technology is not confined to the packing shed, and with many table grape growers still field packing, larger scales capable of handling 9- or 10-kilogram cartons can help improve speeds and reduce giveaway.

Scales with target-based outputs like traffic lights have been around for a long time - typically in more sophisticated and costly models for automated processes. Recently, this feature has been added to lower-cost packing scales, making it a viable option for packing sheds that often have dozens of scales.

In fact, many modern electronic scales have the capability to send outputs to lights or buzzers, although a lot of users may not realise this functionality exists. It is certainly worth checking with your local scale supplier or manufacturer.

This article was originally published in The Vine, a joint publication of the Australian Table Grape Association (ATGA) and Dried Fruits Australia (DFA).