A project has completed the first phase. During the lessons learned meeting, the project manager reported that the project was successful because it was on time, on budget, and on scope. The sponsor…

Not following a change control plan would likely lead to scope creep or unapproved changes, which is not the core issue described here about benefit realization.

Inaccurately defined acceptance criteria would impact whether the deliverables met functional requirements, but not necessarily the higher-level, long-term organizational benefits like cost reduction.

While important, the project management plan details how the project will be executed, monitored, and controlled, but the specific realization of long-term organizational benefits is often managed at a higher level.

Project benefits like cost reduction and system response time are often strategic outcomes that extend beyond the project's direct deliverables and timeline. These benefits are typically outlined in a benefits management plan, which is usually managed at the organizational or portfolio level to ensure their realization post-project completion, not solely within the project management plan. The project manager focuses on delivering the project's scope within time and budget, while benefit realization belongs to the ongoing operations or strategic management.