Conduct and document a lessons learned review

Jeremy Curtis

Published: Aug 27, 202612 min read

Purpose of the step

The purpose of Step 5 is to evaluate how commissioning performed on past, comparable projects and carry those findings forward before making the same decisions on the current one.

This directly implements the predesign objective in [ASHRAE Guideline 0-2019, Section 5.1.3(e)], which requires the "review and use of lessons-learned information from previous projects" before design begins.

A Note on ASHRAE Timing: Do not confuse this with the formal Project Lessons Learned Workshop. Under [Guideline 0-2019 Section 8.2.1.3(g)] and [SSPC 300 Annex 05], that workshop is a post-occupancy activity typically held around month 11 of operations.

Essentially, Step 5 is a preparatory phase that fulfills the Predesign requirements of [Section 5.1.3(e)]. By completing this review and building a Lessons Learned Register first, you ensure the team is fully equipped before they even begin the Owner's Project Requirements (OPR) workshop.

In practical terms, this step ensures that:

✅ Known failure patterns from previous projects [late CxP appointment, vague OPR requirements, inadequate testing windows, weak training, unusable Systems Manuals] are documented before the OPR is written in [Stage 1, Step 7], preventing the team from rediscovering the same issues throughout the project.

✅ The OPR workshop is structured around what previous projects got wrong, not just what the current team hopes to get right.

✅ The Cx Plan and programme minimums reflect specific risks identified from the Owner's own portfolio, rather than generic commissioning good practice applied without evidence.

✅ Where no formal lessons learned process exists in the Owner's organisation, that gap is itself recorded as a finding and escalated for action.

Inputs and Outputs

Required Inputs

Expected Outputs

CxP appointed with independent authority and defined scope.

Lessons Learned Register: A structured list of recurring failure patterns, positive practices, and recommended mitigations for this project.

Accepted Cx Organisation Chart confirming which Owner functions can supply prior project records.

OPR Workshop Discussion Topics: Structured questions mapped directly to OPR content sections.

Meeting and reporting protocols established, including agenda and distribution requirements.

Source Document Index: Traceability record of all historical documents requested, received, and reviewed.

Escalation paths and team cohesion protocols confirmed.

Organisational Findings Note: Flagged portfolio-level governance gaps for Owner action beyond this project.

Historical project documentation: Lessons Learned information, Previous Cx Reports, Issues Logs, defect lists, and post-occupancy evaluations.

Step Checklist

Comparable previous projects have been identified and agreed with the Owner's Representative as the review universe.
All available lessons learned materials and substitute records [logs, reports, surveys] have been formally requested.
Received documents have been catalogued in a Source Document Index noting project, date, document type, and any known gaps.
Records have been systematically reviewed across the seven key commissioning areas defined for this step.
Recurring failure patterns and positive practices have been identified, with root causes documented rather than symptoms alone.
A Lessons Learned Register has been completed: each finding records pattern, evidence, root cause, priority, and recommended action for this project.
High-priority findings have been translated into specific OPR workshop discussion topics mapped to OPR content sections.
Findings with programme or scope implications have been flagged [SCOPE] or [PROGRAMME] in the register; each flag identifies the step at which it must be actioned [Stage 1, Step 9[, [Stage 1, Step 10], or [Stage 1, Step 13] and has been confirmed with the Owner's Representative.
The draft register has been circulated to the CxP Team, including FM and O&M representatives, and updated based on their input.
The finalised register has been issued to the CxP Team with a clear instruction that selected findings must be addressed in the OPR and reflected in the Cx Plan.
Owner Organisational-level gaps have been documented in an Organisational Findings Note and escalated to the Owner.

How to

This section covers the sequence for conducting a lessons learned review across six sub-steps, from defining comparable projects to finalizing the register with the team. Work through them in order to ensure historical failure patterns actively shape the Owner's Project Requirements (OPR) workshop before design begins.

Quick reference:

4a: Identify and agree on comparable projects to review
4b: Request and assemble lessons learned source material
4c: Analyse records for recurring failure patterns
4d: Build the Lessons Learned Register
4e: Translate findings into OPR workshop inputs
4f: Review and finalise the register with the CxP Team

Many project teams make the mistake of reviewing only the past projects that are easiest to access, rather than those that are genuinely relevant. Relying on a few easily remembered projects produces weak, unconvincing findings and misses the recurring patterns that a broader review would reveal. To prevent this, you must define clear comparability criteria and agree on the final project sample with the Owner's Representative before requesting any documents.

Work with the Owner's Representative to define what makes a past project "comparable." Use clear criteria: facility type, system complexity, contract type (such as design-build), and size. Projects that share at least three of these criteria with the current project qualify as comparable. Document these rules so your selection process is clear and auditable. If the Owner's past projects are too small, too old, or not similar enough, do not settle for a poor sample. Instead, agree on alternative methods with the Owner's Representative before requesting documents. Acceptable alternatives include: using projects from other industries that have similar system complexity; using published benchmark data from ASHRAE or BCxA; or using the Commissioning Provider's (CxP) own past projects, provided the Owner gives explicit consent and these are marked as external projects in the Source Document Index.
Confirm which of the selected projects had a formal commissioning scope (following Guideline 0 or Standard 202). This ensures your review focuses on projects that had official commissioning requirements, rather than projects that only had basic, informal installation checks.
Prioritize recently completed projects. For recent projects, the Operations and Maintenance (O&M) teams can still remember specific commissioning failures clearly, the performance data matches current Owner standards, and the project conditions are similar enough to provide useful lessons.
Agree on the final list of projects to review with the Owner's Representative in writing before sending any document requests. Keep a record of any projects that were considered but excluded, along with the reason why. This written document becomes the Comparable Project Review Agreement. It is an official output of this step and serves as the official tracking record for every future document request and analysis decision. This agreement must be fully signed before you ask for any project documents.

What to Watch

Practice drift to watch for: selecting past projects based on what is easy to access rather than what is genuinely comparable. Reviewing a small, convenient sample produces findings that look anecdotal and miss the recurring patterns a proper review is designed to find.

Common Issues

IssuesWhat it looks like in practiceWhy it causes trouble

Review scoped to the most accessible projects rather than the most relevantTwo or three projects are reviewed because someone on the team remembers them clearly; no formal comparability criteria are applied; the Owner's Representative is not consulted on the review universe.Findings look anecdotal and are easily dismissed. Patterns from projects with different delivery methods or system complexity are missed entirely, and the register is too thin to drive meaningful Owner's Project Requirements (OPR) changes.

Evidence base relies on verbal recollections rather than documentsThe team conducts informal interviews and builds the register from memory rather than retrieving available commissioning records, Issues Logs, and post-occupancy reports.Findings have no traceability. When a finding conflicts with a stakeholder preference at the OPR workshop, there is no document to point to. The register is challenged and, frequently, set aside.

Root causes not identifiedThe register lists incidents and symptoms rather than diagnosing causes (e.g., stating "CxP appointed late" without exploring what contract or schedule structure produced that outcome).OPR and Commissioning Plan changes address symptoms only. The structural conditions that produced the failure are unchanged, and the same pattern recurs on the current project under a different label.

Register completed but not integrated with OPR workshopThe register is issued as pre-reading material but does not drive the workshop agenda, discussion topics, or time allocation across OPR content sections.The OPR is written as if no previous experience existed. The same requirement gaps from previous projects reappear in the new OPR because no one used the register to structure the session where those requirements were being discussed.

Project CxP facilitates the review session rather than participating as a contributorNo independent facilitator is appointed; the CxP, who produced the register, chairs and facilitates the review meeting. Other participants are less likely to challenge findings or raise gaps when the person being reviewed is also running the room.The review becomes a validation exercise rather than a genuine challenge. Root causes are softened, gaps are missed, and the register reflects what the CxP believes happened rather than what the broader team experienced.

Review starts too lateThe lessons learned review begins after OPR workshop dates are already set, or after the first workshop session has been held.Findings arrive as a post-mortem on decisions already made. Incorporating them requires reworking accepted OPR sections or, more commonly, they are acknowledged and quietly deprioritised.

Organisational gaps noted but not escalatedThe CxP identifies that the Owner has no formal lessons learned process, records it internally, and focuses on project-specific mitigations without raising it to the Owner as an organisational issue.The systemic condition persists. The next project's CxP faces exactly the same absent records and reaches the same conclusions. Nothing changes at portfolio level.

Key Terms

Lessons Learned Review

A structured evaluation of commissioning performance and related outcomes on comparable completed projects, based on documentary evidence and Commissioning Provider (CxP) Team input, conducted before the Owner's Project Requirements (OPR) workshop begins.

Lessons Learned Register

A consolidated, issued document that records recurring failure patterns, root causes, priorities, and specific recommended actions for the current project, structured for active use at the OPR workshop and beyond.

Comparable Project

A previous project in the Owner's portfolio with similar facility type, system complexity, and contract type, with some level of documented commissioning activity to review.

Recurring Failure Pattern

An issue, behaviour, or omission appearing across two or more reviewed projects that materially affected commissioning outcomes, such as late CxP appointment, absent OPR training requirements, or inadequate seasonal testing windows.

OPR Workshop Prompt

Specific questions or discussion points derived from the register and built into the OPR workshop agenda to ensure that known weak areas receive structured attention and produce stronger requirements than previous projects achieved.

Source Document Index

A catalogue of all prior project records requested, received, and reviewed during the lessons learned process, recording document type, project, date, and known gaps. This index is the official traceability record for the review.

Organisational Findings Note

A short memo or flagged register section recording portfolio-level issues (such as an absent formal lessons learned process or absent post-occupancy review protocol) and proposing concrete improvements for the Owner's governance structure beyond this project.

Substitute documents

Commissioning records used in place of formal lessons learned documents where those documents do not exist: Issues and Resolution Logs, defect lists, project handover reports, Systems Manuals, training records, maintenance call histories, and post-occupancy surveys.

Decision Points

This table highlights the critical decisions required to execute this step effectively and enforce its outcomes on the project.

DecisionWho decides

Which prior projects qualify as comparable and must be included in the review sample.Owner / Representative

Which document types Owner functions are required to supply, and within what timeframe.Owner / Representative

How many projects and which themes are sufficient to draw portfolio-level conclusions.Commissioning Provider

Which register findings are selected as mandatory discussion topics for the OPR workshop, rather than advisory notes to consider.Commissioning Provider

How organisational-level findings are escalated, documented, and tracked beyond this project.Owner / Representative

Whether programme or scope implications from findings require formal adjustments to Cx scope, budget, or programme minimums before Stage 1 closes.Owner / Representative

Timing and sequencing

Step 5 begins as soon as the Commissioning Provider (CxP) Team organisation and meeting protocols are established. It continues until the Lessons Learned Register is finalised and issued, which must occur before the Owner's Project Requirements (OPR) workshop [Stage 1, Step 7] agendas are set and pre-workshop materials are distributed.

Earliest start: As soon as [Stage 1, Step 4] is complete and the Owner has confirmed which internal teams hold prior project records and can supply them within the review window.
Latest acceptable start: Early enough that the register can be finalised, circulated to the CxP Team, reviewed, updated, and formally issued before the OPR workshop preparation begins. Leaving insufficient time between issuing the register and the first OPR workshop session is a major sequencing failure.
Dependencies: [Stage 1, Steps 1], [Stage 1, Step 2], [Stage 1, Step 3] and [Stage 1, Step 4] complete; access to the Owner's project archives confirmed; initial CxP Team meeting schedule in place under Step 3 protocols to provide formal review slots for the register circulation and validation meeting.
Parallel activity: The register development does not need to wait for all source documents to arrive before analysis begins. Catalogue received documents progressively and begin pattern analysis on the first tranche; final register compilation requires all documents to be assessed, but preliminary themes can emerge early to inform OPR workshop discussion topics while the full document set is still being assembled.

Roles and Responsibilities

RResponsible

Receive and act on the Organisational Findings Note; authorise programme-level governance changes arising from portfolio-level findings.

AAccountable

Holds ultimate governance authority for the Owner's commissioning programme; escalation destination for findings that exceed the Owner's Representative's authority.

CConsulted

On the Owner's risk appetite for acting on portfolio-level commissioning governance gaps.

IInformed

Of the finalised register, Organisational Findings Note, and their integration into Stage 1 documents.

Documents Produced

This table gathers the governing documents and clauses that support the advice in this article. Use this section as the main map back to sources, so that inline citations in the body can remain selective.

Format / contentWritten agreement recording the comparability criteria applied, the final list of projects in the review universe, any projects considered and excluded with reasons, and any substitute document strategy agreed where the Owner's portfolio is insufficient. Produced at 4a before any document requests are sent.

Where it is usedTraceability record for the entire review. Supports challenges to the representativeness of the sample and audits of the Owner's portfolio commissioning history.

ASHRAE References

DocumentRequirement / practical use in

ASHRAE Guideline 0-2019Sections 5.1.3(e), 5.2.3.1, 7.2.15.1(h), 8.2.1.3(g); Informative Appendices E (E2.4), I, J

Section 5.1.3(e) explicitly establishes the "review and use of lessons-learned information from previous projects" as a predesign objective. Section 5.2.3.1 validates using experiences from similar previous facilities and projects to establish the Cx scope. Section 7.2.15.1(h) requires capturing lessons learned progressively in the Construction Phase Cx Report while information is fresh. Section 8.2.1.3(g) mandates convening a lessons-learned workshop during post-occupancy. Appendix E (Section E2.4) notes that the post-occupancy lessons-learned workshop should be facilitated by an independent member of the CxP's firm. Appendices I and J provide the structure and nominal group technique methodology for conducting the OPR workshop, which is the ultimate destination for the pre-design lessons learned findings.

ASHRAE Standard 202-2024Sections 5.1.1, 6.2.3, 16

Section 5.1.1 establishes the Owner's responsibility to define the commissioning scope and provide necessary project information, which underpins the requirement to formally request past project documents. Section 6.2.3 defines OPR content requirements that register findings must be mapped to as OPR workshop discussion topics. Section 16 governs post-occupancy operations, which provides the framework for the organisational improvement recommendations that come from portfolio-level gap findings.

ASHRAE Guideline 1.2-2019Sections 8.2.7 (1.1) and 8.2.7.2–8.2.7.3 (1.5)

Guideline 1.1 Section 8.2.7 mandates convening the lessons learned workshop. Guideline 1.5 Sections 8.2.7.2 and 8.2.7.3 govern the independent facilitator rule (to avoid conflicts of interest) and provide the structured workshop questions used to frame the lessons learned discussion - note this is for smoke control.

ASHRAE SSPC 300 Informative Annex 04-2024Section 04.4

Establishes the structural format of the OPR, supporting the requirement to include a dedicated "Problems to Avoid / Lessons Learned" section, confirming that the register findings from this step provide the direct source material to shape it

ASHRAE SSPC 300 Informative Annex 11-2022Section 11.1

Provides practical guidance on the structure of Issues and Resolution Logs from previous projects. Since these logs act as the primary substitute documents when formal lessons learned records do not exist, this annex is useful for interpreting historical log content during pattern analysis.

ASHRAE SSPC 300 Informative Annex 15-2022Section 15.1(h)

Section 15.1(h) supports the organisational improvement recommendation that commissioning lessons learned observations should be recorded progressively in Progress Reports throughout the Construction Phase rather than batching them at project closeout.

ASHRAE SSPC 300 Informative Annex 16-2022References and resource list

Useful for identifying supplementary guidance resources when interpreting historical records from projects that used different commissioning frameworks or delivery contexts.

ASHRAE SSPC 300 Informative Annex 21-2024Role descriptions for CxP, Owner, FM/O&M

Provides supplementary guidance on role definitions and responsibilities across the commissioning team, supporting the RACI assignments for this step and the interpretation of role-related findings in historical records.

ASHRAE SSPC 300 Informative Annex 05-2022Section on lessons learned and register documentation

Provides example content for commissioning process plans that incorporate lessons learned findings, useful as a template reference when structuring the register for integration into the Commissioning Plan.