Page "Avionics software" Paragraph 2

The basic idea of any software development model is that each step of the design process has outputs called " deliverables.

" If the deliverables are tested for correctness and fixed, then normal human mistakes can't easily grow into dangerous or expensive problems.

Most manufacturers follow the waterfall model to coordinate the design product, but almost all explicitly permit earlier work to be revised.

The result is more often closer to a spiral model.