Quarry conveyor decisions go wrong when they are made out of order. Belt specification gets fixed before lump size and drop height are agreed, idler spacing is copied from a different site, and the transfer points are left to the fabricator. This guide sets out a sequence that survives a real quarry: material and duty survey first, then belt speed and throughput, then belt construction and cover grade, then the components that take the punishment, then transfer and cleaning, and only then the commercial comparison. Each step lists what to record and which choice it locks in, so the next decision is made with the numbers already on the table.