6.2 Storage volume and space needed
The amount of storage capacity required will depend on the type of storage required. The items and quantities needing to be stored are based on the:
- programme’s needs within a given period
- buffer stocks based on the time necessary to replenish
- contingency stock
- storage requirements and lifetime of products.
To determine the size of the warehouse required, use the volume and floor space needed, rather than the weight of the items to be stored. Extra space is needed to load, unload and repack damaged bags, and will also help with ventilation. A good ratio is 30% for access and 70% for storage.
Storage height depends on the type of items and packaging. A two-metre stacking height is appropriate for the majority of items. Piling over three metres is dangerous and may jeopardise stock at the bottom.
Example of calculation of the storage space required for a distribution of 10,000 rations of four litres of oil, 15 kg of wheat flour and one kg of iodised salt.
Items Net weight (kg) Volume
Oil 40,000 40 * 1.8 = 72 m3
Wheat flour 150,000 150 * 1.7 = 255 m3
Iodised salt 10,000 10 * 0.8 = 8 m3
Total 200,000 335 m3
Note: For some items, consider packaging weight and volume for the calculation.
Storage space with a stacking height of two metres will be: 335 / 2 = 167.5 m2
Suitable surface for access and ventilation is: 167.5 / 7 * 3 = 71.8 m2
The logistician will need roughly 240 m2 (167.5m2 + 71.8m2)
Note: Total weight for the distribution is a key factor for transportation, as it will determine the number of trucks or trips needed.