An overall increase in despatch productivity of 20 per cent has been achieved by WH Smith at its 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 the site. 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, unstable. “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.”
WH Smith is one of the UK's best known retailers. It operates over 500 stores throughout the UK which sell a wide range of products including books, news and magazines, DVDs and stationery. The company's Dunstable warehouse provides national distribution centre services for stationery products and also acts as the principal regional distribution centre for the South of England. There is another major NDC/RDC operation in Swindon, while trans-shipment facilities in Yorkshire and Scotland ensure nationwide coverage.
The Dunstable warehouse, which is owned and operated by WH Smith, has been on the same site for over 26 years and until recently, had no automation. The picking and despatch operations were particularly labour intensive with order picking managed using a combination of trolleys, pallet trucks and totes. A goods lift was used to transfer items between the two floors of the warehouse.
Although this had served the company well in the past it was recognised that improvements were required. Greater productivity with better order picking and assembly accuracy were identified as key requirements. Automation would help eliminate errors made, as despatch staff would previously manually sort consignments to stores by reading the despatch label on the box/tote.
WH Smith reviewed the operation in 2005 and invited five prospective suppliers, including SDI Greenstone, 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.
“We gained a lot of confidence from what existing customers were saying,” says Robin Ritchie. “The feedback we had about SDI Greenstone was superb.”
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.
“This is an excellently engineered solution,” says Robin Ritchie. “And everyone on the site or visiting the site is amazed at how quiet the system is.”
The system was designed to accommodate up to 3000 cartons an hour, providing plenty of capacity for current operations, seasonal peaks and WH Smith's projected growth. The warehouse currently operates round-the-clock five days a week and is busiest during the summer “back to school” and Christmas periods. More than 4000 SKUs are stocked in the Distribution Centre and up
to 2,000,000 units are shipped each week.
The most significant change in operations has been in the case picking area on the ground floor where cases are now picked direct to belt in a single handling movement. Items were previously picked direct from their bin locations onto pallet trucks. This area has experienced the largest productivity gain in the warehouse since the implementation of automation.
“We achieved a 100 per cent productivity gain in this section,” says Robin Ritchie. “In other words, we can now pick twice as much in the same time or the same amount in half the time.”
Another important benefit that was especially noticeable in the case picking area was the reduction of ferrying lift truck movements. Now that case picks are moved by the conveyor there is little need for trucks to operate in the area, apart from replenishment. This has reduced noise, helped to 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 been simplified by the introduction of the sortation system. In the past, the totes were stacked on pallets within the picking areas before being manually sorted by route and transferred to the despatch area using lift trucks/goods lift. 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 allows us to handle over 95 per cent of all picked items; the only limitations being on very bulky or heavy packages” says Robin Ritchie.
In addition to the items picked for delivery to individual stores in its RDC capacity the warehouse also trunks items to the Swindon Distribution Centre and trans-shipment depots for delivery to other nationwide stores.
Orders for these destinations are processed in much the same way as local deliveries. Meanwhile, product picked and sent from Swindon is placed onto a “cross docking” spur of the conveyor so that it can pass through the sortation system and be directed to the correct spur. Both of these facilities have helped reduce the number of handling movements and increased the overall efficiency of transfers between the two main distribution centres.
“As a direct result of our investment in automation we have witnessed a 20 per cent increase in despatch productivity,” says Robin Ritchie.
The equipment was installed by SDI Greenstone in phases during a 12 week programme early in 2006. The conveyor has an in-built SCADA – supervisory control and data acquisition – system that identifies and highlights emerging problems.
Individual sections of the conveyor can be isolated and shut down for routine and remedial maintenance. An onsite engineer carries out routine maintenance tasks and ensures that any unexpected technical issues are addressed before they affect the overall operation.
“I really cannot speak highly enough of SDI Greenstone, its installation team and subcontractors,” says Robin Ritchie. “They completed all the work on time and without disruption to the day to day operations.”
“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.”
Gordon Smith, Managing Director
Tel: 01788 574666
Fax: 01788 574696