The Cost Reality
Agile is not automatically cheaper than Waterfall.
Agile changes the cost profile; it does not remove cost. Frequent planning, refinement, demonstrations, testing, stakeholder engagement and continuous prioritisation all need time from capable people.
It may reduce expensive late rework when learning is genuinely useful. It can also cost more when scope remains open without disciplined prioritisation, when teams attend ceremonies without making decisions, or when operational work is left outside the delivery plan.
Capacity Is a Delivery Commitment
Ring-fenced people and time are essential.
A squad can only make credible sprint commitments when the people and skills required to deliver are protected from competing day-to-day work. Product priorities need matching engineering, testing, security and operational capacity — not simply a target date.
Ring-fencing resources can be difficult for the business when teams are supporting live services and responding to urgent demand. Without that protection, however, work is repeatedly interrupted, sprint targets are missed and product expectations are set without the capacity to meet them.