Interviewing SMEs for GMP Investigations
Subject Matter Expert (SME) interviews can be valuable in GMP investigations.
SMEs often understand the process details that are not fully visible in batch records, procedures, logbooks, audit trails, or test data. They may explain how a task is actually performed, where handoffs occur, what controls are used, what conditions existed at the time of the event, and what may have changed recently.
But SME interviews should be handled carefully.
An interview is not just a conversation. In a GMP investigation, interview information becomes part of the evidence record. It should be planned, documented, evaluated, and connected to other evidence where possible.
As discussed in the broader process described in Pharmaceutical Investigations & CAPA, SME interviews are part of building an evidence-supported investigation record. As discussed in Evidence Collection and Analysis in GMP Investigations, interviews can support investigation reasoning, but they should not replace available records, data, or observations.
Why SME Interviews Matter
Many GMP events involve process context.
A record may show what was entered. A system may show when an action occurred. A logbook may show that a step was completed. But those records may not fully explain the sequence, conditions, interruptions, decision points, or practical constraints around the event.
SME interviews may help clarify:
what happened before, during, and after the event
how the process is normally performed
whether the event followed normal or unusual conditions
what controls were expected to work
whether any recent changes occurred
whether personnel observed alarms, delays, discrepancies, or interruptions
whether the written procedure matches actual workflow
whether the event may be isolated or part of a broader pattern
This makes interviews especially useful for investigations involving manufacturing execution, QC laboratory work, equipment operation, environmental monitoring, cleaning, documentation, material movement, handoffs, and review processes. This is why SME interviews should be planned within the overall GMP Investigation Lifecycle.
Decide Who Needs to Be Interviewed
The investigation should identify interviewees based on the event, scope, and evidence needs.
Possible interviewees may include:
operator or analyst involved in the event
line lead, supervisor, or area manager
QA reviewer or batch record reviewer
QC reviewer or laboratory supervisor
equipment owner or maintenance technician
process engineer or technical expert
validation, automation, or computerized system SME
warehouse, materials, or dispensing personnel
environmental monitoring or microbiology SME
training, document control, or quality system personnel
The goal is not to interview as many people as possible. It is to interview the people who can provide relevant information for the investigation question.
For example, if a wrong material was staged, the investigation may need input from warehouse, dispensing, production, QA, and system support. If an environmental monitoring excursion occurred, interviews may involve manufacturing personnel, cleaning personnel, EM staff, microbiology, facilities, and the area owner.
Prepare Before the Interview
A strong interview starts before the conversation.
The investigator should review available evidence first, such as:
event description
batch record or test record
relevant procedure
equipment or system logs
alarm history
audit trail
training record
prior similar events
timeline of known facts
This preparation helps the investigator ask focused questions.
It also helps avoid asking the SMEs to reconstruct facts that are already available from records. The interview can then focus on context, sequence, practical workflow, decisions made, conditions observed, and potential explanations that need to be tested.
Preparation also helps reduce leading questions.
A leading question may push the interviewee toward a preferred conclusion.
Weak question:
Did you miss the reconciliation entry because you were distracted?
Stronger question:
Can you walk me through what happened during the reconciliation step?
The stronger question gives the interviewee room to describe the sequence without assuming the cause.
Ask Open, Factual Questions
SME interviews should begin with open, factual questions.
Useful questions include:
| Interview Focus | Example Questions |
|---|---|
| Sequence of events | Can you walk me through the activity from start to finish? |
| Normal process | How is this step normally performed? |
| Event conditions | What was different or unusual during this event? |
| Controls | What checks or controls are normally used at this step? |
| Detection | How was the issue first noticed? |
| Handoffs | Who was involved before and after this step? |
| Records and data | Which records or systems would show what happened? |
| Recent changes | Were there any recent changes to the process, record, equipment, material, or staffing? |
| Practical barriers | Was anything unclear, unavailable, delayed, interrupted, or difficult to perform? |
The investigator should listen for facts, timelines, decisions, observations, and conditions.
The interview should avoid blame-based questioning. A blame-focused interview may reduce the quality of information and push the discussion toward defense rather than fact finding.
Separate Facts from Opinions
SMEs may provide both facts and interpretations.
Both can be useful, but they should not be treated the same way.
A fact may be:
The barcode scanner was not available at the dispensing station during the activity.
An interpretation may be:
I think the scanner issue caused the wrong material to be selected.
The interpretation may be important, but it still needs to be tested against other evidence.
The investigation should distinguish:
what the SME directly observed
what the SME performed
what the SME was told by someone else
what the SME believes may have happened
what records or data can confirm the statement
what remains uncertain
This distinction helps prevent interview opinions from becoming unsupported conclusions.
Check Interview Information Against Records
Interview information should be compared with available evidence.
For example,
If an operator reports an interruption, review batch record timing, supervisor notes, room entries, or process logs.
If an analyst reports instrument instability, review instrument logs, sequence data, maintenance history, or calibration records.
If a supervisor reports that a step was performed according to procedure, review the procedure, record entries, and any available system data.
If an SME reports that a condition is routine, check trends, prior deviations, or process observations where relevant.
This does not mean the interviewee is not credible. It means the investigation should support conclusions with the strongest available evidence.
An interview may identify a new evidence path. It may also reveal that the investigation scope needs to expand.
Document the Interview Clearly
Interview documentation should be clear enough to support the investigation record.
It should usually include:
who was interviewed
role or function
date of interview
reason for interview
key questions or topics discussed
relevant facts provided
process context explained
records or evidence referenced
follow-up items identified
unresolved points or uncertainty
The record does not need to be a transcript unless company procedure requires it. But it should be specific enough to show how the interview informed the investigation.
Weak documentation:
Operator interviewed. No issued identified.
Stronger documentation:
Operator stated that the reconciliation entry is normally completed after material charging, not during the step. Operator also stated that the batch record field appears two pages after the charging instruction. Batch record layout was reviewed and confirmed that the reconciliation field is separated from the execution step.
The stronger version shows what information was obtained and how it was checked.
This also supports the final investigation report. As discussed in Writing Defensible Investigation Reports, the report should show how evidence was used to support the conclusion. Interview information should be documented clearly enough that a reviewer can understand what was learned, what was verified, and how it affected the investigation.
Use Interviews to Strengthen Root Cause Analysis
SME interviews can help root cause analysis, but they should not shortcut it.
Interview information may help identify:
task conditions
unclear procedure steps
workflow mismatch
system limitations
equipment behavior
handoff gaps
training or qualification concerns
control weaknesses
recent changes
practical barriers to correct execution
This can be especially important when the initial explanation appears to be human error.
For example, an interview may show that the person did not simply “forget” a step. The process may have required documentation after the activity, the field may have been separated from the instruction, or the system may not have prevented the error.
That information helps the investigation move from a surface-level explanation to a more useful cause analysis.
Common Interview Weaknesses
Common weaknesses in GMP investigation interviews include:
interviewing too late
asking leading questions
documenting only vague summaries
treating opinion as fact
relying on interviews when objective records are available
failing to interview the right function
ignoring conflicting interview information
using the interview only to support a conclusion already selected
failing to identify follow-up evidence from interview responses
These weaknesses can make the investigation harder to defend, especially when the conclusion relies heavily on interview information.
QA Review Questions for SME Interviews
QA review should confirm that interviews were appropriate, useful, and connected to the investigation logic.
| QA Review Question | What the Investigation Should Show |
|---|---|
| Were the right people interviewed? | Interviewees match the event, scope, and evidence needs |
| Were interviews conducted in time? | Relevant information was gathered before memory, conditions, or context became unreliable |
| Were questions neutral and factual? | The interview approach did not assume the cause |
| Were facts separated from opinions? | Direct observations, interpretations, and assumptions are distinguishable |
| Was interview information verified where possible? | Records, data, observations, or trends were checked when available |
| Were conflicts addressed? | Different accounts were reconciled or uncertainty was documented |
| Did interviews support RCA? | Interview findings were used to test causes, not simply confirm a preferred conclusion |
QA Review Perspective
SME interviews can add important process reality to GMP investigations.
They help explain how work was performed, what conditions existed, what controls were expected, and where the written record may not tell the full story. But interviews should be treated as evidence, not informal background discussion.
A strong investigation uses interviews to clarity the event, identify evidence paths, test possible causes, and strengthen the final conclusion.
The best interview records are factual, specific, and connected to other evidence. They help the investigation show not only what people said, but how that information supported the quality decision.
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