How to Plan a Shutdown Survey Schedule

TL;DR

To plan a shutdown survey schedule, work backwards from the outage window: map each survey deliverable to the maintenance task that depends on it, sequence the critical-path measurements first, and time-box every activity against realistic cool-down and access constraints. A schedule built around dependencies — not a flat task list — is what keeps a 36-hour kiln survey from blowing out into 60 and dragging every downstream trade with it.

Key takeaways

• Schedule survey activities by dependency, not by convenience: any measurement that gates fitting, machining or grout (kiln roller adjustment, flange spool fabrication, baseplate levelling) belongs on the critical path and goes first.
• Build the schedule against the outage clock — Australian processing shutdowns commonly run AUD 50,000–500,000 per day in lost production, so a single mis-sequenced survey can cost more than the entire survey contract.
• Allow real cool-down time before precision work: a rotary kiln shell stopped six hours is still 100 °C-plus and thermally expanded; cold alignment to ±1–2 mm needs the shell below roughly 40 °C, which can mean 12–24 hours.
• Match crew and instrument loading to the window — a single Leica MS60 total station crew, a FARO/Leica RTC360 scanning pair, and a CASA Part 101 drone crew can run in parallel on separated work fronts if the schedule deconflicts them.
• Protect the schedule with explicit buffers (15–20% on the critical path) and a written contingency rule for what gets cut first if the outage is shortened.

Why the schedule, not just the scope, decides the outcome

A shutdown survey can be perfectly scoped and still fail commercially. The scope tells you what to measure; the schedule tells you when, in what order, and against which constraint — and it is the schedule that determines whether the survey finishes inside the window or holds up the restart.

The economics are unforgiving. Major Australian processing outages — a SAG mill reline at a Pilbara iron ore plant, a kiln campaign at a Gladstone alumina refinery, a turbine overhaul at a Hunter Valley power station — are costed by the day, and downtime commonly sits between AUD 50,000 and 500,000 per day (McKinsey & Company, 2023). The survey contract might be AUD 8,000–30,000. Get the sequence wrong and you can lose a full day of production waiting for a measurement that should have been taken first.

The difference between a survey that finishes early and one that overruns is rarely instrument capability. It is whether the schedule was built around dependencies and the physical realities of the plant — cool-down, isolation, scaffold readiness, line of sight — or whether it was a flat list of jobs to "get through".

Step 1: Map deliverables to the maintenance critical path (4–8 weeks out)

Start from the shutdown work pack, not the survey scope. For every survey deliverable, ask one question: what maintenance task is waiting on this measurement? That answer sets the priority.

Three patterns recur on Australian sites:

• Kiln alignment data gates roller adjustment. On a rotary kiln (cement, lime, alumina), the cold alignment survey — shell axis, roller skew, mechanical and thermal crank — must be complete and reported before riggers touch the support rollers. The survey is the predecessor; everything else waits.
• Flange and tie-in surveys gate spool fabrication. Laser-scanned as-built dimensions of an existing flange face or pipe rack feed isometric and spool drawings. The spool cannot be cut until the scan is registered and modelled.
• Foundation and baseplate levels gate grout. Levelness and bolt-position surveys must land before grout pours are scheduled, because the pour is irreversible.

Anything on this list is critical-path survey work and is scheduled first. Everything else — general as-built scanning, condition documentation, "while we're in there" capture — is float and gets slotted around the critical work.

Tip: Get the shutdown scheduler to give you the Primavera P6 or MS Project network for the outage. Find the survey tasks, look at their successors, and you have your priority order in minutes — no guessing.

Step 2: Time the schedule against physical constraints, not optimism

A task list assumes everything is accessible the moment the plant stops. It never is. Three constraints reshape almost every shutdown survey schedule.

Cool-down. Thermal expansion is the enemy of precision alignment. A rotary kiln shell that has been stopped for six hours can still be over 100 °C and dimensionally expanded by tens of millimetres along its length. Cold alignment to ±1–2 mm typically needs the shell below roughly 40 °C — which on a large kiln can mean 12–24 hours of cooling. Schedule the survey after that window, or specify a hot kiln alignment using the appropriate hot-survey method and accept the reduced accuracy. Do not schedule cold work into hot steel.

Isolation and permits. Lock-out/tag-out, confined space entry permits and hot work permits are scheduled events, not formalities. A vessel internal scan cannot start until atmospheric testing clears and the entry permit is live, with a standby person rostered. Put permit issue on the schedule as a predecessor task.

Access readiness. Survey crews bring instruments, not scaffold. If the schedule has the survey team at the kiln girth gear at 0600 but the scaffold crew is not finished until 1400, you have eight hours of paid standby. Tie each survey task to the completion of its access provision (scaffold, EWP, manlift) in the network.

Tip: Walk the access route a week before shutdown against the schedule. A locked gate, a height restriction on a manlift, or a missing platform found on the walk is a schedule fix; found on shutdown day it is an overrun.

Step 3: Sequence and load the crews and instruments

With priorities and constraints set, sequence the work and decide how many crews and instruments you need to fit the window.

Most ISS shutdown work is run by deconflicting parallel fronts so the calendar compresses without the crews colliding:

The constraint on parallelism is interference, not geography alone: heavy rigging or grinding next to a total station ruins the measurement, and airborne dust from cleaning degrades a laser scan. Sequence precision measurement before or clear of disruptive trades on the same front.

All work ties back to site control — GDA2020 / MGA2020 horizontal and AHD vertical — so plan the control re-establishment or verification as the first scheduled survey task. Downstream measurements cannot start until control is confirmed.

Tip: A second total station crew or a second scanner is often cheaper than a day of extended downtime. When the window is tight and the critical path is dense, schedule for parallel crews rather than a single crew working longer shifts — tired crews on hour 14 make mistakes that cost re-measurement.

Step 4: Build a realistic timeline with buffers

Lay the sequenced tasks onto a calendar that mirrors the outage. A worked example for a kiln-and-mill shutdown:

Two buffer rules keep this honest. First, add 15–20% buffer to the critical-path duration — outages rarely run to plan, and the buffer absorbs late access or atmospheric clearances without pushing the restart. Second, schedule preliminary results to flow within 24 hours of each critical measurement so adjustment work (roller moves, shimming) can start before the final report, rather than waiting days.

Common scheduling mistakes to avoid

Scheduling cold alignment into hot steel. The single most expensive timing error: surveying a kiln or large rotating asset before it has thermally stabilised. The data is wrong, the rework is real, and the re-survey eats the window. Put the cool-down clock on the schedule explicitly.

Treating survey as a single block instead of dependency-linked tasks. A "2-day survey" line on the shutdown bar chart hides the fact that one measurement inside it gates a rigging crew. Break the survey into its constituent tasks and link them to their successors.

No contingency rule. When the outage is shortened — and it often is — an undefined survey scope means panic and arbitrary cuts. Decide in advance, in writing, what is critical-path (always done) and what is float (cut first).

⚠️ Watch out: The worst combination is a tight, optimistic schedule with no buffer on a fixed-price contract. When site unreadiness causes standby, the day rate extends and you pay for waiting. Either schedule realistically with buffers, or expect the planned duration to slip and budget for it.

Frequently asked questions

How far in advance should I plan the shutdown survey schedule?

Begin mapping survey deliverables to the maintenance network 4–8 weeks before the outage, and lock the sequenced schedule 2–4 weeks out. Engage the survey contractor early — peak Australian shutdown seasons (roughly March–May and September–November) book out, and late engagement limits both contractor choice and your ability to schedule parallel crews.

Where does the survey sit on the shutdown critical path?

Any survey whose result gates an irreversible or fitting-dependent task — kiln roller adjustment, spool fabrication, grout pours, baseplate machining — is on the critical path and is scheduled first. Survey work that only produces documentation is float and is slotted around the critical measurements.

How much time should I schedule for cool-down before alignment?

For cold alignment of a rotary kiln or large rotating asset, schedule enough time for the shell to fall below roughly 40 °C — commonly 12–24 hours depending on size and ambient conditions. If the window cannot accommodate that, schedule a hot kiln alignment instead and accept the reduced accuracy. Confirm the requirement with your surveyor before fixing the timeline.

Can survey activities run in parallel with other shutdown trades?

Yes, on separated work fronts. Total station alignment, laser scanning and drone capture can run concurrently in different areas. The limit is interference: vibration from heavy rigging corrupts precision measurement and airborne dust degrades scan data, so precision work must be scheduled clear of disruptive trades on the same front.

What happens to the schedule if the outage is shortened?

A well-built schedule has the answer written in before shutdown: critical-path surveys are completed regardless, float items are deferred. Because the tasks are dependency-linked rather than a single block, you can shed the non-critical work without holding up restart. This is exactly why dependency-based scheduling beats a flat task list.

Request a quote

A shutdown survey schedule that respects dependencies, cool-down and access constraints is what turns precision measurement into on-time restart. Industrial Spatial Solutions plans and executes shutdown survey schedules across Australian mining, cement, alumina, power and processing sites — building the survey sequence into your outage network, loading crews and instruments to fit the window, and delivering preliminary results fast enough to keep downstream work moving.

Call 0407 057 015 to scope and schedule your next shutdown survey. Early engagement means the schedule is right before the plant ever stops — and the clock is on your side when it does.