With the rise in online shopping pushing up the demand for UK warehouses, rents and purchases of storage space are likely to rise and so it is imperative to maximise the efficient use of the space chosen, while never forgetting the importance of the safety factor. Today, there are many kinds of racking and shelving to suit specific needs, some safer than others, but to get the best out of them a full survey of the stored products’ dynamics must be conducted for each group of products stored, especially in a multi-channel sales scenario. This will look at the volume flows by SKU throughout the year, product sizes, weights, time sensitivity, packaging and hazard ratings. It may also be necessary to look at the interface type of handling equipment. Would, for example, articulated forklifts be preferable to reach or conventional counterbalance forklifts owing to their potential to exploit big space savings? And if picking speeds and accuracy are critical, especially to meet JIT delivery schedules, will it be worthwhile to add pick-to-light to live storage schemes?

Nobody ever said that warehousing today was straightforward but more than ever today the price for getting it wrong can be the difference between Clover Street and Carey Street. Fortunately, there are simulation tools to make the choice of right warehouse storage design easier, either from independent software providers or the in-house departments of large, wellestablished, racking suppliers.

There are also some good consultants that might be worth considering. If, however, thinking about a new-build warehouse it may be wise to consider contracting out at least part of the warehouse function, particularly if seasonal demand is such that it would not make sense building in a lot of spare, often empty, capacity to cope with huge seasonal, demand swings. To cope with those swings it could be more efficient to use a shared user 3PL warehouse. One recent trend, however, shows that it may pay to specialise exclusively in a warehouse geared only to serve online shoppers directly.

The design of warehouses and how they are built could be governed by the degree of automation involved. In large projects where operators are looking to store higher than 25 mt the clad rack method would be cheaper and quicker to build than conventional constructions. Favoured by fully automated warehouse operators, this method relies on the racking going up first and then attaching the warehouse shell.

Sometimes the racking choice is made easy by the highly specific nature of the stored products and dynamics. Cold store operators, for example, with an eye on huge energy bills which can absorb 25% of operating costs, will favour high storage densities achieved by drivein, mobile and live racking. Mobile racking can offer at least 50% more density than fixed, narrow aisle APR as well as 100% selectivity.

There is, however, a penalty to pay in slower product access times because aisles much first be opened before loads can be accessed. Here, bolted mobile racking would be preferable owing to reported weld failures on mobiles in very low temperatures. Mobile racking’s initial cost may be three times higher than APR and so in view of that many cold store operators favour drive in/drive through racking, which offers the same storage density as mobiles. Drive-in, however, only suits batch picking because instant selectivity is a poor average of 30% and is based on first-in last-out, unless it is drive/through but that would pose a space loss penalty.

Drive-in is also notorious for relatively high damage levels in view of the tight tolerances in which forklifts must work. Live racking can cost twice as much as drive-in racking but buyers should consider the wider aspects because live racking could emerge one third cheaper than drive-in. One study, for example, shows the average utilisation of drive-in racking is only 66% compared with 90% for live storage. And in comparison, the latter can save 12.5% of ground area. All that has implications for building and running costs.