Stationary on the move
February 1st 2007 An advanced sortation system from SDI Greenstone has resulted in a 20% increase in despatch productivity at WH Smith's distribution centre in Dunstable Following the introduction of an advanced automated sortation system from SDI Greenstone, WH Smith has reduced costs, increased order picking accuracy and improved efficiency throughout its Dunstable distribution centre. The new system has specifically eliminated many powered pallet truck movements and manual handling operations to help promote better health and safety within the site. "This project was all about reducing the cost base, whilst improving the overall productivity of the site," says Robin Ritchie, distribution centre manager at WH Smith, Dunstable. "Although the site was built 26 years ago, the site was well configured for the adoption of automation and it has greatly helped optimise our operation. Accuracy of product shipped to our stores has very much improved since the installation of the sortation system." The Dunstable warehouse provides national distribution centre services for stationery products and also acts as the principal regional distribution centre for the South of England. Until recently, there had been no automation at the site – picking and despatch operations were particularly labour intensive using a combination of trolleys, pallet trucks and totes. A goods lift was used to transfer items between two floors. WH Smith reviewed the operation and invited five prospective suppliers to propose automated solutions based on its outline requirement. The company visited a number of reference sites and spoke to users to assess the different proposals before selecting the solution from SDI Greenstone. SDI proposed an automated sortation system to link the principal sections of the warehouse, including case picking, tote picking, order assembly and despatch to create a highly efficient picking environment. The automation interfaces with the warehouse management system to ensure that order picking is synchronised with delivery routes and schedules. The system is designed to accommodate up to 3000 cartons an hour, providing capacity for current operations, seasonal peaks and projected growth. More than 4000 SKUs are stocked in the round-the-clock facility and up to 2,000,000 units are shipped each week. The most significant change has been in the ground floor case picking area, where cases are now picked direct to belt in a single handling movement. Items were previously picked direct from bins on to pallet trucks. "We achieved a 100% productivity gain in this section," says Ritchie. "In other words, we can now pick twice as much in the same time or the same amount in half the time." Reduced lift truck movements Another important benefit in the case picking area is the reduction of ferrying lift truck movements. Now case picks are moved by conveyor there is little need for trucks to operate in the area, apart from replenishment. This has reduced noise, helped eliminate a potential health and safety hazard and allowed staff to undertake different tasks. Lift trucks are now primarily used to load transport vehicles. The conveyors link three main picking areas before cartons and totes arrive on the sortation loop. The picking operation within the tote picking areas remains largely the same, with items being picked into totes carried on picking trolleys, although the overall process has now simplified by the sortation system. The totes are now simply placed on the conveyor and the automated system moves the totes directly to despatch where they arrive pre-sorted by route. During the transfer of cartons and totes to despatch the conveyor passes through a series of scanners which read the despatch labels. Both omni-directional and fixed head scanners are used to ensure that all labels can be read whether they are placed on the top or side of the cartons. The sortation system identifies the totes/cartons as they pass the scanners and then automatically redirects them to one of ten spurs which corresponds to the appropriate delivery route. At this point the totes/cartons are sorted into individual stores. The scanners also automatically send a file back to the warehouse management system confirming shipment to the various stores. The conveyor system handles over 95% of all picked items; the only exceptions being very bulky or heavy packages. The equipment was installed by SDI Greenstone in phases during a 12 week programme early in 2006. "SDI Greenstone do not just take an order, install and walk away. They still look to continually optimise the automation in order to maximise the benefits. This automation sortation system was a huge cultural change for the Dunstable team and they needed to adapt to the change very quickly indeed. With the support and expertise of SDI Greenstone, the transformation from a predominantly labour intensive operation to an automated environment was almost seamless" concludes Richie. More articles from SDI Group UK Limited: | 
