At what point do projects with low Systems Engineering effort begin to show difficulty in predicting cost overruns?

The correct answer is that projects with low Systems Engineering effort tend to show difficulties in predicting cost overruns within the range of 0% - 200%. This range indicates that as the project progresses, particularly in the early stages, the lack of thorough Systems Engineering practices can lead to significant unpredictability in costs.

During the initial phases of a project, the unclear definition of requirements and inadequate risk management can result in unforeseen challenges and expenses as the project evolves. The broader range signifies that even a small amount of additional complexity or unaddressed requirements can lead to substantial increases in expenses as the project scope expands or changes unexpectedly.

Projects with insufficient Systems Engineering may not adequately assess or manage risks early on, leading to escalated costs that can exceed initial estimates dramatically. The nature of Systems Engineering involves ensuring that both technical and management aspects are harmonized and that clear requirements are established and met. Hence, when these factors are neglected, the ability to accurately predict project costs becomes severely compromised, which is reflected in the wide range captured in the answer.