When does schedule variance in projects start to decrease according to SE effort?

The point at which schedule variance starts to decrease, according to systems engineering (SE) effort, is recognized at 12% SE effort. This figure is critical in project management, particularly within the domain of systems engineering, as it highlights an essential threshold where initial investments in SE efforts begin to yield improvements in the project's schedule adherence.

At this 12% SE effort level, the organization has engaged enough systems engineering practices—such as requirements management, architecture development, and verification & validation processes—to effectively start mitigating risks and addressing potential issues before they escalate into larger problems. This proactive approach allows for better management of resources, streamlined systems integration, and an overall reduction in the variance between the planned schedule and the actual timeline of project activities.

In contrast, the other options may suggest levels of SE effort that are either too low or portray significantly higher thresholds that do not align with established project management models. Recognizing the optimal SE effort early in the project's lifecycle can set the foundation for achieving project milestones more efficiently and ensuring that projects remain on track.