Agile versus waterfall, deliveries and risk !
Observe how the risk decreased in time in the agile methodologies and at the same increase in Waterfall methodologies. As well the first delivery is delivered in a early stage in agile even the risk for failure is high since this is only a partly product, but in waterfall the risk is huge in the end when everything is delivered to the customer. But it requires that the customer also are able to think iterative and can accept partly deliveries and start testing it before the complete products are done.
Note! If users and customers don’t start testing at first delivery and attend the iterations the risk will increase quickly. If management thinks waterfall and the project run agile, the fail rate increases dramatically. many project fails due to management and customers expect full deliveries but developers work agile and deliver partly, the clue here is communication and that product owner and steering boards are involved.