According to the PMBOK Guide, specifically the Monitor and Control Project Work and Control Schedule processes, a Project Manager must validate information before taking corrective or preventive actions.
Validation First: When a new Subject Matter Expert (SME) provides feedback that a schedule was " not assessed properly, " the Project Manager's first responsibility is to verify the accuracy of this claim. The PM cannot act on an opinion without first performing a technical Review of the Schedule Baseline.
Schedule Crashing Analysis: Crashing is a schedule compression technique used to shorten the duration for the least incremental cost by adding resources. Before crashing, the PM must review the baseline to identify the Critical Path. Crashing only works on critical path activities; crashing non-critical activities provides no benefit to the project end date.
Integrity of the Baseline: A baseline is a formal, approved version of the schedule. It should not be changed (Option A) or modified via a change request (Option C) until a thorough analysis proves that a change is necessary and beneficial.
Professional Judgment: By reviewing the baseline with the SME, the PM can determine if the original assumptions were flawed or if the SME has identified a legitimate opportunity to optimize the project timeline.
Analysis of other options:
Option A: Updating the schedule baseline is a premature step. A baseline is only updated after a Change Request has been formally approved by the Change Control Board (CCB).
Option C: Initiating a change request is a " doing " step. You cannot justify a change request until you have conducted the Review (Option B) to understand the impact on cost, scope, and resources.
Option D: While the SME ' s feedback might suggest a risk, the primary issue raised is about the current assessment and optimization of the schedule. Updating the risk register is a secondary administrative task that follows the technical review of the schedule itself.
Per PMI standards, when new technical expertise suggests an error or opportunity in project planning, the Project Manager must first Review the Schedule Baseline to perform an impact analysis and validate the findings before taking further action.