A Sales tunnel (also calle a Sales pipeline, or a Sales funnel to emphasise the volumetric changes in deals) is the way that both direct sales persons and SFA systems visualise the sales process of a company. In any step of the sales process prospects drop out of it, and from the large number of initially interested persons on the narrow end of orders only a fraction of the initially interested people remain and actually place an order. The structure may start at various process steps (e.g. a sales lead, or later, a sales offer) to a closed/finished contract or Deal Transaction.