In the Internet age where consumers are ever-more demanding over delivery times the “intelligent” conveyors play a key role in gaining competitive advantage but there are so many conveyor types that it is difficult to know where to begin. The choice can be narrowed down if one’s conveyed products are more or less homogenous, like in the fashion industry which often favours overhead conveyors for hanging garments. Even so, says James Sharples, MD of Swisslog, “automation has to be used wisely in order to be effective,” adding that the value of consultancy “cannot be stressed enough”. Consultancy, of course, does not necessarily mean bringing in outside consultants, like systems integrators, because many of the big automation houses now have their own, in-house consultancy divisions and software capabilities, which means that if a scheme goes wrong as, indeed, they still do, there is only one butt to kick and no tiresome buck passing.

The connection between conveyors and stock-holding costs, enhanced sales ability and even transport costs may not be readily obvious but the importance of this has not been lost on John Lewis, who stock over 350,000 lines across fashion, home and technology. Back in 2007, the company wanted to have a ‘sell one, pick one’ replenishment strategy to minimise stock in its distribution network and free up back-of-shop stores to create more sales area. In some ways this strategy is the best form of stock forecasting exercise, though that is not to denigrate slick forecasting programs that can react in real time to changes in daily weather forecasts, which are capable of cutting stocks by one third without harming customer service levels. But to implement such a strategy it needed automation to improve performance, speed and accuracy. This it has achieved with help from its logistics automation partner, Knapp, so that today more than 90% of its stock assortment at its Magna Park 1 and 2 sites is broken down into single selling items rather than warehouse packs, which previously caused over replenishment.

All large retailers today have large, rapidly-growing online business but it comes at a price, namely e-commerce orders cost three to four times more than placing traditional stock in shops. Moreover, one must have the ability to consolidate goods fast so that, for example, clothing on hangars can be consolidated with other goods like binnable items (stored in totes) and all to be delivered within 24 hours or less. In John Lewis’s case the overhead conveyors allow them to process clothing on hangers for consolidation with other goods, based on Knapp’s trolley-less conveyor whereby hangers are carried directly on the conveyor, allowing both single items and blocks of garments to be moved on the same system.

Today such overhead conveyors have harnessed information technology to give a level of control that turns them into factories in the key. Such is their flexibility that they can buffer, divert, raise or lower, load or offload, select specific items and sort, position at an ergonomic height and report on their own state of function and the position of items it has transported. They can interface with other devices like AGVs, robots and lifts and also communicate with warehouse management systems.

While overhead conveyors may initially be 8-13% more costly than ground-based conveyors and access for maintenance more problematic it is the life cycle costs that should be of overriding concern. Even so, big ticket automation investment schemes rely critically on top line maintenance because any downtime could be disastrous. In John Lewis’s case, to avoid this they are supported by Knapp’s resident customer service team that carries out a comprehensive programme of preventative maintenance. If your automation scheme is less ambitious so that an on-site maintenance service is unaffordable or seemingly unjustified then at least ensure you have a same-day call-out service to minimise downtime. The aftersales maintenance service is the Achilles heel of any highly automated handling scheme.