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

For a Product or Service whose consequence of failure is low, the framework proceeds to the structural chain, and the first link in that chain is Decomposability. Decomposability asks whether the body of work can be partitioned into small units at all. It is a question about the structure of the work: does the work admit being broken down, or is it an indivisible whole?

Decomposability is assessed against the body of work as a whole, not by examining individual units one at a time. The presence of small units inside a body of work proves nothing on its own — a Waterfall-shaped effort also contains many small units. The question is whether the work, taken in its entirety, can be reduced to small units, allowing for a reasonable number of unavoidable exceptions. Work that resists being made entirely of small units — work that contains irreducibly large, indivisible elements beyond what counts as reasonable exception — fails the Decomposability indicator.

A body of work that cannot be partitioned into small units is, by that fact alone, directed to Waterfall. Iterative delivery has nothing to iterate over if the work cannot be broken down. The work is a monolith, and a monolith is delivered as a bounded, integrated effort. Only a body of work that passes the Decomposability indicator continues to the next link in the structural chain.