Principles of Warehouse Design - Internal and External Layouts

Chapter 5 Internal and External Layouts an extract from “Principles of Warehouse Design” Mike Oliver, Partner, Total Logistics 5a Market Place Wokingham Berkshire RG40 1AL UK General Principles Ensuring a good operational layout in a distribution facility, both internally and externally, will have a significant positive impact on labour productivity and facility throughput capacity. Taking into account the fixed costs associated with investment in land and buildings, plus annual charges associated with a facility, it is worthwhile investing time to optimize the layout of the site and buildings. An increased annual throughput reduces the fixed cost per case or item handled. In designing a good operational layout, there are a number of general principles that should be applied: • Allow movements to take place in a logically sequenced flow • Avoid cross-traffic and bottlenecks • Avoid unnecessary movement or travel • Allow sufficient space buffer between process steps A further operating principle that impacts on the design process is to de- couple the resources allocated to critical tasks or activities. As a simple example, a delay in a putaway process could impact on both the goods receipt function and the replenishment of picking locations. Overall Flow The overall flow through a site and facility should be considered by the following elements: • Inbound vehicles bringing goods to the site • Outbound vehicles taking goods to their next destination • Internal materials movements as part of the distribution centre process Clearly the timing and intensity of each of these activities will impact the optimum layout for the operation. Likewise the detail of the operation, in terms of the volume of goods received and despatched will be highly significant. 2 Layout Tools and Techniques Materials Flows The recommended starting point is to develop the warehouse flow diagram, described in Chapter 2, into a materials flow chart for the operation (see Figure 5.1). This should represent the expected activity levels for a defined period, such as an average day. As far as possible, all processes should be incorporated in the flow chart, and it is important to ensure that an activity can be assessed in sufficient detail. As an example, goods receipt volumes of 26 pallets in an average hour might be a single articulated trailer, or 26 light vans carrying a single pallet on each delivery. Similarly, the activity and labour required to process a single pallet of one product code will be far less than a mixed pallet of many products. Inbound Processing Infeed Store Picking Despatch Local Supply # 40,732 Cases Hand Toting Infeed to Tote MiniLoad MiniLoad Store Toted and Secure Secure Sequencer 2,780 SKUs # 89 Pallets 550 SKUs 550 SKUs 550 SKUs 550 SKUs 50 SKUs 267,528 Cases 45,258 Cases 45,258 Cases 6 days 271,548 Cases 45,258 Cases 15% 6,789 Cases 2,535 Pallets # 4,526 Cases 99 Pallets 99 Pallets 594 Pallets 99 Pallets Pallets Totes # 10 Pallets 2,468 Totes 2,468 Totes 14,808 Totes 2,468 Totes 370 Totes Cages Cages Cages Cages Cages 46 Cages 226,796 Cases 8 totes/cages 2,446 Pallets Allocation Picking Tote Sequencer 50 SKUs 500 SKUs ## 30,424 Cases 38,469 Cases ## 362 Pallets Pallets Totes 2,098 Totes 32 cases/cage 951 Cages 262 Cages Containerised Hand Palletising Infeed to ASRS ASRS Bulk Store 1,995 SKUs SKUs SKUs 1,077 SKUs 36,708 Cases 32,182 Cases 258,978 Cases 16 days 4,143,648 Cases Bulkies 1,087 Pallets 32,182 Cases 1,077 Pallets 3,523 Pallets 56,368 Pallets 15 SKUs Totes 1,077 Pallets Totes Totes - Totes 5% 15,212 Cases Cages Cages Cages Cages ## 543 Pallets Totes 14 cases/cage 1,087 Cages bulkies Despatch SKUs Standard Pick 304,236 Cases 4,210 SKUs Pallets 189,004 Cases 2,468 Totes 2,328 Pallets 9,013 Cages - Totes 32 cases/cage 5,906 Cages standard A Lines Drinks Household Total 20 5 25 SKUs 7% 1% 21,297 3,042 24,339 Cases 7% 1% 254 36 290 Pallets Totes 666 95 761 Cages Figure 5.