Commissioning and Handover Planning
Last reviewed 9 September 20262,778 words13 min read
Systems completion, MC/PC and punch lists — the last 15 % of the job that takes 30 % of the time
🟩 In one line: From about month −6, the schedule stops being about areas and becomes about systems — build the T&C node system by system (mechanical completion → pre-commissioning → commissioning → integrated testing → authority inspections → taking over), let the sectional milestone close only behind that chain, and put the energisation date on the critical path where it belongs.
👤 Who this is for: Mid-level planners approaching the last six months; senior planners setting up the T&C node at baseline. Prerequisites: Milestones-and-key-dates, Procurement-and-long-lead-items, Wbs-structure-design.
First, let's be honest about why this page exists
Most baselines end with "Testing & Commissioning — 90 days" and "Snagging — 60 days" hanging off the last finishes activity. Then the substation is energised eight weeks late, the chillers cannot be run, the BMS cannot be proven, the civil-defence inspection cannot be booked, and the schedule that showed 40 days of float in month 20 shows −55 in month 26.
Commissioning is a chain of dependent, gated events with authorities in it. It is more predictable than most construction because the sequence is fixed by physics — you cannot balance air before the fans run, and the fans do not run before permanent power. The planner's job is to model that sequence early enough that the energisation date and the long-lead plant are seen as the critical path they are.
🟨 The standard — what "good" looks like
| Source | What it says (paraphrased) | Use it for |
|---|---|---|
| FIDIC 1999 Cl 9.1–9.4 / 2017 Cl 9.1–9.4 | Tests on Completion: pre-commissioning, commissioning, trial operation; notice before tests; delayed tests; retesting (check the edition in your contract) | The three stages and the notice lead |
| FIDIC 1999 Cl 10.1–10.3 / 2017 Cl 10.1–10.3 | Taking over of the Works and Sections when substantially complete and Tests on Completion passed; minor outstanding work permitted; interference with tests (check against your copy) | What "complete" means; punch list survives taking over |
| FIDIC 1999 Cl 11 / 2017 Cl 11 | Defects Notification Period; outstanding work completed | Post-handover activities |
| FIDIC 1999 Cl 4.1 / 2017 Cl 4.1 (Contractor's documents), Cl 1.8 | Operation and maintenance manuals, as-built documents required before taking over (check against your copy) | Documentation chain in the schedule |
| NEC3 / NEC4 Cl 11.2 (Completion definition), Cl 30.2, Cl 35, Cl 40–42 | Completion when work per Scope done and defects not preventing use corrected; take over; tests and inspections; correcting defects (check against your copy) | Completion criteria live in the Scope |
| ASHRAE Guideline 0 The Commissioning Process | Cx process phases: pre-design through occupancy; functional performance testing; systems manual | Stage names and what each proves |
| CIBSE Commissioning Codes (A, B, C, L, M, R, W) | System-specific commissioning sequence and management | Durations and dependencies per system |
| BSRIA BG 8 Model Commissioning Plan (or current equivalent) | Commissioning plan structure, witnessing, documentation | The commissioning plan the schedule follows |
| DCMA 14-Point, items 1, 5, 8; GAO Best Practice 2 | Logic complete, constraints minimal, durations staged; hand-offs sequenced | T&C chain testing |
| Hub convention | Standing WBS nodes T&C and Milestones; sectional milestones follow T&C; Duration % on approvals and reviews; INTERFACE-IN milestones for utility and authority dates | Your defaults |
🟢 Rule: no completion milestone closes off a finishes activity — it closes off the last inspection certificate in a system-based chain that starts at permanent power.
How it actually works
1. Switch the WBS from areas to systems. Construction is by area; commissioning is by system. Under the standing T&C node:
| Level | Content |
|---|---|
| T&C | Standing node |
| → Systems group | Electrical (MV, LV, generators, UPS, lighting, earthing); Mechanical (chilled water, AHUs/FCUs, ventilation, smoke control); Public health (domestic water, drainage, hot water); Fire (detection, alarm, sprinklers, fire pumps, voice evacuation); Vertical transport; ELV (BMS, access control, CCTV, PA, data); Façade (water tests, BMU); Architectural completion (by area, then by Section) |
| → System | e.g. Chilled water system 1 |
| → Stage activities | See table below |
Each system's chain is 8–15 activities; a tower has 40–80 systems; a hospital 150–250. The T&C node ends up with 600–1,500 activities on a hospital — and that is right.
2. The stage chain per system.
| Stage | What it proves | Typical duration (working days) | Gate before it | % type |
|---|---|---|---|---|
| Installation complete (per area, in the construction WBS) | Physically installed, IR'd | — | — | Physical |
| Mechanical completion (MC) — system | All components installed, tagged, pressure/flush tests done, MC punch list at Category A zero | 5–15 | All area installs for the system | Physical (checklist count) |
| Static / pre-commissioning | Dead tests: insulation resistance, pressure, flushing, point-to-point | 5–20 | MC; temporary or permanent power | Physical |
| Energisation / first run | Permanent power available and switched | Milestone | Utility connection, MV approval, LV inspection | — |
| Commissioning — system | Set to work, balancing, regulation, controls loop-tuned | 10–30 | Energised; water treated; BMS points available | Physical |
| Functional / performance testing | Proven against design under load, witnessed by Engineer | 5–15 | Commissioned; Engineer notice (Cl 9.1 / Cl 40) | Physical |
| Integrated systems testing (IST) | Cause-and-effect: fire alarm → smoke control → lifts → access control → generator | 10–20 per Section | All life-safety systems FT'd | Physical |
| Authority inspections | Civil defence, utility, municipality, lift authority | Application lead 10–20 + inspection + re-inspection | IST passed; documents submitted | Duration % (approval-type) |
| Documentation | O&M manuals, as-builts, training, spares | 20–40 parallel | Commissioning data | Duration %, steps |
| Snagging / punch list closure | Category B items to zero, Category C agreed | 10–20 per area/floor | Architectural completion per area | Units complete (items) |
| Taking over / Completion certificate | Milestone | — | All above per Section | — |
3. Put energisation where it belongs. The permanent power chain — MV switchgear delivery → substation civils → utility inspection → connection → energisation — is the single most common critical path in the last six months of a Gulf building. Model it as: utility application (INTERFACE-IN with the application lead as a numbered assumption) → substation handover to utility → utility inspection → connection → energisation milestone. Then every commissioning stage that needs load is FS from energisation. Temporary power lets you do dead tests and some running; it does not let you commission chillers or prove the generator changeover. Say which stages run on temporary power in the SBM.
4. Authority chains. Each approval is apply → authority period → inspection → response → (rectify → re-inspect) → certificate. The authority period is a numbered assumption with the source (current published service standard, or the last three projects' achieved lead). One re-inspection cycle in the baseline for civil defence. Authorities are named as neutral context only.
5. Integrated testing and the Section. IST is per Section and requires every life-safety system in that Section functionally tested. The sectional completion milestone is FS from IST passed, civil-defence certificate, and architectural snag closure for that Section. Nothing else closes it.
6. Punch lists in the schedule. Snagging is not a 60-day bar. Per floor or area: joint inspection (2–3 days) → rectification (5–15 days by trade, Physical % on items closed) → re-inspection (2 days) → area sign-off milestone. Punch list count is the quantity; the snag register is the quantity sheet. Category A (prevents completion) must be zero before the taking-over milestone; Category B/C carry into the DNP under a Post-Handover node with the FIDIC Cl 10.1 "minor outstanding work" list attached.
7. Codes and layouts. Add System as a project-level code (controlled values by system tag) so a system's chain can be filtered across the construction and T&C nodes. Layout 07 Systems: grouped by System, sorted Early Start, showing MC / energised / commissioned / FT / IST milestones as columns via UDF dates. Commissioning manager's weekly report is this layout with a 4-week window.
📜 What the contract lets the schedule say
- Notice before tests — FIDIC Cl 9.1 (21 days' notice of readiness for Tests on Completion — verify per edition); NEC Cl 40.3 (Supervisor and Contractor notify each other before tests). The notice lead is an activity, not a lag, on the 7-day calendar.
- Employer-caused test delay — FIDIC Cl 9.2 / 2017 Cl 9.2 (check against your copy); Cl 10.3 interference. If the Engineer cannot witness, the activity's actual finish is held and the notice clock (28 days) starts from the missed date.
- Taking over with outstanding work — FIDIC Cl 10.1 permits taking over when the Works are substantially complete with minor items outstanding. That is the contractual basis for the Category B/C split; the schedule shows the split so the argument is ready.
- NEC Completion — defined by the Scope (Cl 11.2). If the Scope says "all commissioning complete and O&M manuals delivered", documentation is on the critical path to Completion. Read the Scope's completion definition before building the chain.
- Sectional taking over — see Milestones-and-key-dates; each Section has its own IST and its own certificate chain.
🟥 Where people go wrong
- T&C as one bar per building. "T&C — 90 days" has no energisation gate, no authority in it and no system order. When power is late nobody can say what moves. Build it by system; 90 days becomes 600 activities and the driver becomes visible.
- Energisation assumed. The baseline shows chillers commissioning in month 22 with permanent power "expected"; the utility application was never scheduled. The utility chain is an INTERFACE-IN sequence with an application lead as a numbered assumption from day one.
- Authority periods as zero. Civil-defence inspection booked the day IST finishes and passed the same day. Apply → period → inspect → re-inspect, each an activity, one re-inspection in the baseline.
- Snagging as an afterthought. A 60-day bar starting the day finishes end. Per area, per trade, with a count, from the last four floors onward while the top floors are still in second fix.
- Documentation ignored. O&M manuals and as-builts start in the last month and the taking-over certificate is refused for want of them. Documentation is 20–40 days per system group, starting at commissioning, on the path to Completion where the contract says so.
- Commissioning on the construction calendar. Chiller commissioning in July on an 8.5-hour day, in a sealed plant room, with the Engineer's witness unavailable for Eid. Use the site calendar with real exceptions; consider a night-shift calendar for external plant.
- Temporary-power capacity never checked. The plan runs six AHUs on temporary power that can carry two. Write the temporary-power stages in the SBM and check the load with the electrical subcontractor before the baseline.
⚖️ When you're challenged
"We finish the last floor in March; why does completion show June?" Because the last floor's second fix isn't what closes the Section — the integrated systems test is, and that can't start until every life-safety system is functionally tested, which can't start until the substation is energised, which is forecast for late March. The chain is on layout 07 system by system.
"Can't we compress T&C? Ninety days is just a number." Most of it is gated, not resourced: you can't balance air before the fans run under permanent power, and the civil-defence inspection has a booking lead. The compressible parts are pre-commissioning and snagging, and those are already overlapped with construction. What compresses the end date is energisation, and that's the utility chain.
"The Employer says the building isn't complete because the O&M manuals aren't in." Under Clause 10.1 taking over is on substantial completion with minor outstanding work permitted, and the outstanding-works list is attached to the certificate request. Whether manuals count as minor depends on the Employer's Requirements — that's a contract question, but the schedule shows manuals finished 12 days after the IST, and that gap is what we're discussing.
"Who's late — us or the utility?" The interface register shows the substation was offered to the utility on 14-Jan against a planned 10-Jan; their inspection happened 12-Feb against the 15-working-day published lead. Four days ours, 19 theirs; notice N-023 covers the 19 and was issued within the 28 days.
📄 Related pages
- Milestones and Key Dates — sectional milestones, Key Dates, what closes them
- Procurement and Long-Lead Items — the plant that has to arrive before MC
- Engineering and Design Schedule — the review chain reused for authority approvals
- Subcontractor and Interface Integration — utility and authority dates as INTERFACE-IN milestones
- FIDIC Time Clauses — Cl 9, 10, 11 in the wider time framework
- NEC Accepted Programme — Completion defined by the Scope
- WBS Structure Design — the T&C standing node and the System code
- Activity Coding Structure — adding System as a project code
✏️ Worked example — Riyadh hospital, Section 2 (inpatient tower), T&C chain at DD 25-Mar
Contract FIDIC 1999 Red; Section 2 Time for Completion 30-Sep; Tests on Completion notice 21 days; Section requires IST, civil-defence certificate, health-authority inspection.
| ID | Activity | Dur (d) | Pred | Early Start | Early Finish | TF |
|---|---|---|---|---|---|---|
| IF-060 | Utility inspection of substation S2 (INTERFACE-IN, SOoA per application ref U-114) | 0 | — | 08-Apr | — | 0 |
| TC-ELE-S2-020 | Utility connection & MV energisation | 8 | IF-060 | 08-Apr | 17-Apr | 0 |
| MS-510 | Section 2 energised | 0 | TC-ELE-S2-020 | — | 17-Apr | 0 |
| TC-ELE-S2-030 | LV distribution live testing, floors 1–8 | 12 | MS-510 | 18-Apr | 02-May | 0 |
| TC-MEC-S2-110 | Chilled water system 2 — commissioning & balancing | 22 | MS-510, MC-CHW-2 | 18-Apr | 15-May | 0 |
| TC-MEC-S2-120 | AHUs 2-01 to 2-14 — commissioning | 25 | TC-MEC-S2-110 SS+10 | 02-May | 03-Jun | 0 |
| TC-MEC-S2-130 | Isolation-room pressure regime proving | 10 | TC-MEC-S2-120 | 04-Jun | 15-Jun | 0 |
| TC-FIR-S2-210 | Fire alarm & smoke control — functional testing (Engineer witness, notice 21 cal d) | 15 | TC-MEC-S2-120, TC-ELE-S2-030 | 04-Jun | 22-Jun | 3 |
| TC-IST-S2-300 | Integrated systems test — Section 2 | 15 | TC-MEC-S2-130, TC-FIR-S2-210, lifts FT, generator FT | 23-Jun | 12-Jul | 0 |
| TC-AUT-S2-410 | Civil-defence application & period (20 wd assumption A-31) | 20 | TC-IST-S2-300 SS | 23-Jun | 20-Jul | 0 |
| TC-AUT-S2-420 | Civil-defence inspection, rectify, re-inspect | 12 | TC-AUT-S2-410, TC-IST-S2-300 | 21-Jul | 05-Aug | 0 |
| TC-AUT-S2-430 | Health-authority inspection & response | 15 | TC-AUT-S2-420, snag closure L1–L8 | 06-Aug | 25-Aug | 0 |
| TC-DOC-S2-510 | O&M manuals, as-builts, training — Section 2 | 40 | TC-MEC-S2-110 SS+15 | 09-May | 10-Jul | 28 |
| MS-220 | Section 2 — Time for Completion (FOoB 30-Sep) | 0 | TC-AUT-S2-430, snag sign-off | — | 25-Aug | +27 |
Read: 27 working days of float to Section 2 completion, all of it dependent on the utility inspection on 08-Apr (IF-060). A 4-week utility slip consumes it entirely. The narrative names IF-060 as the driver, states the application was lodged 12-Feb against the 40-working-day published lead, and lists the one lever that does not depend on the utility: bringing AHU commissioning forward on temporary power for the four units the temporary supply can carry (SBM §9 temporary-power table), saving an estimated 6 days, SOFT-RES, approver MEP manager.
📖 References
- FIDIC Conditions of Contract for Construction 1999, Cl 1.8, 4.1, 9.1–9.4, 10.1–10.3, 11 (check the edition in your contract)
- FIDIC Conditions of Contract for Construction 2017, Cl 1.8, 4.1, 9.1–9.4, 10.1–10.3, 11 (check the edition in your contract)
- NEC3 / NEC4 ECC, Cl 11.2, 30.2, 35, 40–42 (check the edition in your contract)
- ASHRAE Guideline 0, The Commissioning Process (check against your copy)
- CIBSE Commissioning Codes A, B, C, L, M, R, W (check against your copy)
- BSRIA BG 8, Model Commissioning Plan (check against your copy)
- DCMA 14-Point Schedule Assessment, items 1, 5, 8; GAO Schedule Assessment Guide GAO-16-89G, Best Practice 2
- Oracle Primavera P6 Professional User Guide — Activity codes; UDFs; Layouts (check against your P6 version)
From the field
Experience from working planners. Unreviewed — read it as experience, not guidance.
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