Plan on total lead time, not transit time — the sailing is often the most predictable part of the journey. Total lead time is production or preparation, plus inland haulage to port, plus port dwell and export clearance, plus the sailing or flight, plus import clearance and destination haulage. Sea freight is the default for commodity volumes and is the cheapest per unit but the slowest, and it is the leg where port congestion and documentation delays add the most variance. Air freight is dramatically faster and is the standard choice for high-value, perishable or sample consignments where the freight cost is small relative to goods value. Road freight dominates intra-African corridors and is where checkpoints and border procedures, rather than distance, drive the timeline. The practical planning points: port dwell time and customs clearance vary far more between African corridors than sailing times do, so model the corridor rather than the distance; pre-clearing documentation before arrival is the single most effective way to avoid demurrage and detention, which are the least predictable costs in the whole model; and always ask a supplier for lead time in days from order rather than accepting a range, because a quote that is 4 percent cheaper and six weeks later is usually a loss once storage and missed season are counted.