Steve Richmond, Director of Jungheinrich UK Ltd’s Systems and Projects Division, considers reasons for the growing interest in very narrow aisle (VNA) storage systems and describes developments in automated VNA technology.
The harsh economic climate has forced all businesses to look for ways of maximising the cost and performance efficiency of their assets. People, processes and equipment are being scrutinised as never before as companies from all industry sectors seek to make the most of what they have.
When it comes to the supply chain, one consequence of this ‘asset sweating’ philosophy has been a general reluctance to ‘trade up’ to bigger distribution centres.
“Companies have chosen to look to increase storage density and pallet capacity at their current site without incurring the type of costs that a move to new, larger facilities would involve,” says Steve Richmond, director of Jungheinrich UK Ltd’s Systems and Projects Division.
As a result of this approach, there has been a noticeable upturn in interest in Very Narrow Aisle (VNA) storage systems.
“Significant advantages can be gained by moving from a wide aisle to a narrow aisle storage configuration and, by making better use of an existing facility by increasing storage capacity, many organisations have realised very worthwhile financial benefits,” says Steve Richmond.
However, a switch to VNA storage is not right for everyone, as Steve Richmond explains: “Each application must be analysed individually. There are many factors that come into play – not just the type of forklift truck or materials handling equipment to be employed.
“For instance, reconfiguring the racking into narrow aisles will normally have operational considerations and may also impact on sprinklers, fire protection, lighting, heating etc. All of these factors must be taken into account.
“Other variables that must also be considered from the outset include, stock profile and product mix, operating environment and conditions as well as throughputs and the ratio of full pallets to picking within the storage cube.”
He continues: “VNA offers a higher density of storage than a conventional wide aisle warehouse layout, but this must be balanced against requirements for flexibility and accessibility to products and stock. The analysis and design process must look at all the base data, parameters and deliverables before an optimised solution can be developed.
“Of course, today’s VNA machines offer a high degree of flexibility by combining the ability to handle pallets to lift heights of up to 17 metres and order pick from every level at every storage location. At facilities where order picking is the main focus, VNA trucks can also be utilised for high level picking of small parts or unit loads very efficiently.
“In addition, as most VNA trucks are manufactured for a particular customer or specific application, then load handling devices and order picking platforms can be customised to suit their proposed application or operation.”
So, when it comes to calculating the return on investment for VNA trucks, what are the key factors to consider?
According to Steve Richmod, it is essential that emphasis is placed on the whole life cost of the VNA machine from the outset of a project.
“A VNA truck may be initially more expensive than alternative options but the user must consider a host of other often less than obvious cost savings that VNA trucks will bring, such as reduced product and equipment damage as well as a longer life expectancy than with some alternative equipment types,” he says.
“In instances where a new build is being considered rather than an upgrade of an existing site, there may also be significant cost savings to be made in the overall design and build cost by using a VNA system. For example, a reach truck might be able to serve racking up to 12 metres high but a VNA system can go to 17 metres – meaning that the footprint of the building can be smaller and, as a result, savings can be made on rates and other building-related costs. When it comes to developments in VNA handling equipment, as well as the ongoing emphasis on achieving higher reach heights (VNA trucks are now operating in applications where, as recently as five years ago, only stacker cranes would have been considered) and increasing travel speeds in the aisle between locations, there is a growing trend towards automation based on conventional VNA truck technology.
“Many customers are acknowledging the potential benefits of automated VNA – particularly for two and three shift operations,” says Steve Richmond. “Productivity and efficiency is increased while labour costs are reduced significantly. Automated VNA machines work consistently 24/7 without degradation of work rate or lost time for battery charging or changing and work at a consistent, highly efficient rate throughout the entire shift.”
He continues: “These days automated VNA trucks can be almost completely based on a standard truck which is fitted with an ‘automation package’. This modern approach centres around the adaptation of existing technologies rather than a desire to ‘reinvent the wheel’ – as was the case 20 years ago when the accepted wisdom was to take a truck, strip out all the major components from it and introduce a whole new control system.
“Today we can start with a standard VNA truck with wire guidance and transponder technology and, by introducing additional sensors for profile checking, centering and various other safety-related functions, adding a bus bar and automation controls for the truck’s sensors and fitting an interface to the warehouse management system – the truck becomes fully automated.
“This approach makes automation scalable. Trucks can be supplied as manual machines, upgraded to semi-automated vehicles and ultimately to fully automated systems as the client’s requirements change.
“However, as with any automation project, it is important to ensure that the system is planned and designed by a company experienced in automation and integration as the legislation and working practices for automated VNA trucks differ significantly from manual operations.
“That said, existing VNA facilities can usually be automated with little or no modifications. But design, safety and system integration must be treated as integrated project – not just a truck supply contract and we are perfectly positioned to provide this entire end to end design and implementation process to our customers.”
For more information: www.jungheinrich.co.uk