When does a programmer enter the implementation phase of the waterfall approach?

In the waterfall approach to software development, the implementation phase begins after the requirements have been thoroughly defined and all preliminary phases, such as analysis and design, are completed. This phase is marked by the actual programming work where the developers start writing code according to the specifications laid out in the earlier phases.

This means that when programming has commenced, it signifies that the project has moved from planning and designing stages into the active development of the software. During this phase, the focus shifts to turning the theoretical plans into functional software.