Sizing and specification

Separate the maximum from the usual. The load in a requirement is often the heaviest trip, not the everyday weight: if most loads are under 2 tonnes and heavy ones only occasional, moving those with several robots together or with manual help costs much less; if loads really are heavy every time, two robots working together are often more flexible than one oversized robot. Loads beyond the standard range require a fully customised robot, with price and lead time assessed separately.

The figures in a requirement are often a combination of worst cases, such as “lift to 8 metres and carry 1.5 tonnes”. Analysed separately, they often have a cheaper and safer answer: heavy goods on the lower levels and light goods higher up; one model for 6 to 8 metres and standard products below 6 metres, with the dispatch system assigning tasks in batches; and heavy goods kept in one row, so the other aisles can be narrower and hold more.