Agile, Waterfall, or Hybrid: An IF4IT Framework for Choosing Delivery Methodology

The second link in the structural chain is Incremental Deliverability. It asks whether the small units of the work can be delivered progressively, each delivered increment having standalone value. It presupposes Decomposability — there is no point asking whether units can be delivered incrementally if the work cannot be partitioned into units at all — but it is a genuinely separate question, and the distinction between the two is important.

Decomposability asks whether the work can be partitioned. Incremental Deliverability asks whether the resulting units can be delivered one at a time, each providing value on its own, accumulating toward the whole. These are not the same property, and a body of work can satisfy the first while failing the second. The clearest illustration is an aircraft. An aircraft is highly decomposable — it partitions into wings, fuselage, avionics, landing gear, and thousands of further subassemblies. But an aircraft cannot be delivered incrementally. The enterprise cannot deliver the wings to the customer, let the customer use the wings, and then deliver the fuselage in the next cycle. The increments have no standalone value, and the aircraft provides value only once it is assembled in its entirety. The aircraft is decomposable yet not incrementally deliverable.

This distinction is the reason Incremental Deliverability is a separate indicator rather than part of Decomposability. Agile delivery does not depend merely on the work having been broken into small pieces; a Waterfall aircraft program also has small pieces. Agile delivery depends on small pieces being delivered one at a time, each providing standalone value, accumulating iteratively. Incremental Deliverability, not Decomposability, is the property that genuinely distinguishes work that can be delivered the Agile way. A body of work that is decomposable but whose units have no standalone value when delivered — the aircraft case — is directed to Waterfall. Only a body of work whose units can be delivered as individually valuable increments continues to the final link in the structural chain.