What distinguishes the single-step development approach from the evolutionary development approach?

The single-step development approach is characterized by delivering all capabilities at once, meaning that users do not receive any useful functionality until the entire system reaches what is defined as Initial Operational Capability (IOC). This contrasts with the evolutionary development approach, which is designed to provide incremental updates or capabilities over time. Under the evolutionary model, users can utilize portions of the system as they are developed, promoting continuous improvement and operational usefulness throughout the process.

In the context of system development, reaching IOC in a single-step approach means that there is no interim version of the product that can be utilized by the user, which can lead to a longer wait for the operational capabilities. This contrasts sharply with evolutionary development, where users can benefit from an early version of the product while subsequent versions are still being developed.

The statement regarding incremental updates directly reflects the nature of the evolutionary approach, while the mention of a fixed end-state in relation to the evolutionary model suggests a misconception, as the evolutionary development is typically flexible to adapt to changing requirements. Lastly, the idea that both deliver capabilities simultaneously contradicts the fundamental principles that distinguish these two development strategies. Thus, the key element that sets the single-step development approach apart is that users must await full deployment to access any operational capabilities.