Power plant outage planning that scopes every job from condition data and shows what each finding does to the return-to-service date
Outages scoped right, so they finish on time.
See one case, screen by screen ↓An outage scope is built from many places at once: open and deferred work orders in the maintenance system, inspection and wall-thickness surveys in PDFs, vibration and performance trends in the historian, OEM bulletins, the plan template from the last outage, and contractors' proposals. The critical-path schedule lives in another tool, and the two are joined by people in spreadsheets and meetings. When a survey finds tubes under minimum wall three weeks before breaker open, the planner learns what it does to the return date only after re-running the schedule by hand.
So scope found late becomes the overrun, and every outage day is replacement energy bought in — and, at a steam unit that also feeds a desalination plant, water made the expensive way. Time-based items carried over from the template take crew-hours, crane time and critical-path days that the condition data says are not needed. Two contractors book the same crane on the same shift. And the lesson from the last outage that would have saved a day is in a register nobody opened.
Estimated split for one late condition finding on a major overhaul, in working days, by hand and with the solution.
Seven agents read the evidence, build the scope and place every job on the critical path; the planner chooses and the outage manager signs.
Lumina Utilities' Harrowgate Bay Unit B4 is a 320 MW steam unit that also supplies steam to desalination unit D4. Outage B4-26, a major overhaul, opens the breaker on Mon 2 Nov 2026 at 06:00 and returns the unit on Mon 30 Nov: 28.0 days. Today is T-20, and the scope freezes in 3 days. Here is what happens next, screen by screen, in the working solution.
Mariam owns the scope and the network for B4-26. Her home is the time-scaled network: 26 jobs and 286 work orders across days 0–30, lanes for unit, turbine, generator, boiler, balance of plant and water, the critical path in red. The header reads 28.0 days on plan, return Mon 30 Nov, boiler float 1.0 day — near-critical. The scope inbox shows three items waiting: the new boiler survey at the top, a feedwater pump seal leak and a challenged chemical clean.
“An outage day at Harrowgate Bay: $412,000 — replacement energy $318,000 · auxiliary-boiler water $94,000”
Switched to Evidence, the same network is coloured by why each job is in the outage: condition evidence, statutory, OEM interval, or no evidence and challenged. Of 286 work orders, 198 are justified by a condition reading, 31 are statutory, 31 are past the OEM interval and 26 were challenged.
“Challenges took the outage from 31.0 to 28.0 days in August: the LP turbines are clean, so they stay closed.”
Each challenged item says where it came from, what the challenger looked for and what it found. The boiler chemical clean came from the B4-20 plan template; tube sample TS-B4-0926 shows 18 g/ft² of deposit against the 40 g/ft² trigger, so the proposal is to defer it to B4-28 and keep 2.5 days off the boiler path. For the ID fans it proposes a split: keep 4A, rising at 4.8 mm/s, defer 4B, flat at 2.1 mm/s for 18 months.
Statutory items are never challenged · the evidence challenger proposes, the planner decides, the outage manager signs after the freeze.
Survey UT-B4-0926 by Corrin Inspection Services, raised by boiler engineer Yusuf Demir at 08:12, found 14 front-wall tubes below the 4.10 mm minimum wall at burner level; the thinnest, tube 47 at 31 m, reads 3.62 mm, thinning 0.38 mm a year since 2022. Tube 52 already leaked on 17 Sep and forced the unit off for 5.2 days. Mariam adds it. The reader goes through all 1,152 readings and cites page 6, table 3; the scope builder drafts the job — 840 crew-hours, 56 m of tube, $212,000 — and joins the open pad-weld work order WO-B4-41620.
Readiness tracker: “40 m of tube in stock; 16 m from Arlo Steel, ETA Tue 27 Oct, needed day 15.”
Placed after the superheater pendant repairs — same welders, same scaffold lift — the job puts the boiler on the critical path. The network redraws: 30.0 days, return Wed 2 Dec, boiler float 0.0 days. Priced at the value of an outage day, that is $824,000, and the turbine path now has 2.0 days of float.
“The front-wall job made the boiler path critical: +2.0 days. Return moves from Mon 30 Nov to Wed 2 Dec · +$824,000 at $412,000 a day.”
The advisor offers a parallel way, citing lesson L-B3-25-07: sister unit B3 replaced 9 front-wall tubes on nights in 2025 and saved 1.5 days. Kestrel Fabrication prefabricates 2-tube panels before the outage, and a second crew fits them through 7 window cuts on nights, days 8–12. Mariam swaps: back to 28.0 days, boiler float 1.0 day, $775,400 net avoided.
“Back to 28.0 days. The panels go in on nights, days 8–12, beside the pendant repairs; the boiler keeps 1.0 day of float. Night crew $48,600 against $824,000 of outage days.”
The job page shows the front wall as a map of 128 tubes by 9 elevations, coloured by wall: 14 below 4.10 mm, 22 on the 4.10–4.60 mm watch list. Margin notes cite the survey page and table, the forced outage and design calculation DC-B4-PP-017. The work package runs from isolation and confined-space entry through 100 % radiography of the 28 welds and a re-survey of the 22 watch tubes, with each material's quantity and status.
Margin note: “Against survey UT-B4-0322 (March 2022), the burner zone thinned 0.38 mm a year. The 22 watch tubes reach 4.10 mm in about 18 months.”
Scope change SC-B4-26-014 goes to Tomas with the finding, the options and their effect. Option A, in place after the pendants: 30.0 days, $1,036,000 with the outage days. Option B, panels on nights: 28.0 days, $260,600. Mariam raised and placed it, Yusuf confirmed the evidence, and Tomas signs as outage manager. The panel order goes to Kestrel and the baseline is updated.
When signed: panel order to Kestrel Fabrication (7 panels, ready Thu 29 Oct) · night crew booked days 8–12 · work package WP-B4-26-287 issued · baseline updated.
Headcount follows the network: 88 people on site at the peak, day 5. On that day Halden Turbine Services' HP rotor lift, on the critical path, and Brightline Scaffolding's scaffold deck lift both need the 40 t crane on the day shift. In B4-22 the same clash cost the rotor 7 hours. The fix is one button: move the deck lift to the night of day 4.
Readiness tracker: it finds the clash and never books a contractor — Grace moves the lift.
The milestone line runs from T-180 to breaker open, with the work-package milestone at T-30 missed at 93 %. The checklist covers work packages, materials, contractors, the crane, isolations and permits, the outage notice and the water plan for D4. Materials at risk are listed by need date against ETA: the HP diaphragm seal strips arrive a day after they are needed, and the condenser tube plugs are not yet ordered.
“D4 on auxiliary steam from Unit B3 · 52,000 m³ a day · approved by Water Operations”
The same outage, seen by the five people who own it — what the weeks before breaker open looked like, and what they look like now.
Seven agents read the evidence, build the scope and place every job on the critical path; the planner chooses and the outage manager signs.
Reads inspection reports, wall-thickness surveys, vibration, oil and thermography trends and OEM bulletins; extracts every reading with its location, unit and limit, computes the rate against the previous survey, and links it to the scope item it justifies.
Turns findings, deferred work orders and OEM bulletins into scope items: job steps, materials with quantities, crew-hours by trade, permits and the contractor, joining any open work order on the same equipment.
Looks for a reading, test, bulletin or statutory rule behind every scope item; challenges any with none, saying where it came from, what it looked for and what it found, and proposes defer, split or keep with the days and hours it carries.
Places each job on the outage network with its logic, crew and shared resources, runs the forward and backward pass, and reports the change to the end date, the critical path and the float, priced at the value of an outage day.
When a job lengthens the critical path, looks for ways to take it off — a second crew or shift, prefabrication, different access, a different window — prices each in days and dollars, and cites the lesson that supports it.
Watches materials against need dates, contractor mobilisation, permits, shared-resource clashes such as the 40 t crane, and the milestones to breaker open.
Matches lessons from past outages on this and sister units — the registers of B4-22, B3-25 and B1-24 — to the current scope items.
Signs every change after the freeze. The agents propose; a named person decides.
Ask about any job, finding, contractor or date on outage B4-26 — or say what to change. Every answer points to its records.
Why is the front-wall tube job in the scope?
Because the survey says so. UT-B4-0926 found 14 front-wall tubes below the 4.10 mm minimum wall at burner level; the thinnest, tube 47, reads 3.62 mm. Tube 52 already leaked on 17 Sep and forced the unit off for 5.2 days. The minimum wall comes from design calculation DC-B4-PP-017. It is condition evidence, so it will not be challenged.
What does the tube job do to the critical path?
Done in place after the pendant repairs, it puts the boiler on the critical path: +2.0 days, return Wed 2 Dec, about $824,000 at $412,000 a day. Done as prefabricated panels on nights beside the pendants, it costs 0 days and $48,600 — how B3 did it in 2025.
Which scope items have no evidence?
26 of 286 work orders had no reading, test or bulletin behind them. 9 are deferred to B4-28 (1,940 crew-hours, $462,000), 11 were kept once evidence was found, and 6 are open — among them the boiler chemical clean (18 g/ft² against 40, 2.5 days on the path). The LP turbines were the big one: deferring them took the outage from 31.0 to 28.0 days.
Are we ready for breaker open on 2 November?
91 % ready at T-20. Three things need someone this week: work packages are at 93 % against the 100 % milestone missed on 3 Oct; the 40 t crane is double-booked on day 5; and the HP diaphragm seal strips arrive a day after they are needed. Isolations, the outage notice and the water plan for D4 are done.
13 screens from the working solution, on its sample data. Pick one to see it large.
The freeze, the value of an outage day, what counts as evidence and who signs are settings, chosen by the station.
| Setting | Default | Choose from |
|---|---|---|
| Scope freeze | Fri 16 Oct (T-17) | Fri 16 Oct (T-17) · Mon 19 Oct (T-14) · Fri 9 Oct (T-24) |
| Value of an outage day | $412,000 (energy $318,000 + water $94,000) | $412,000 · $380,000 at the winter energy price — used to price every option |
| Near-critical when float is | 2.0 days or less | 2.0 days or less · 1.0 day or less · 3.0 days or less |
| Condition reading counts when | Within 36 months | Inspection, UT, vibration, oil, thermography, performance test — statutory items are never challenged; items with no evidence always are |
| Challenge a time-based item with no reading in | 24 months | 24 months · 12 months · 36 months |
| Propose defer when the reading is below | 50 % of its trigger | 50 % · 30 % · 70 % of its trigger |
| Ask the plant engineer before a defer | On | On · Off |
Every figure is labelled: a target the solution is built to, an estimate, a typical published result, or a proven one.
“demo” = seen in the working solution, on its sample outage data · “target” = the design goal, measured in the live solution · “estimated” = our estimate · “typical” = published figures (a Portland General Electric regulatory filing on a coal unit outage, 2006 — $450,000–700,000 a day of replacement power; INPO AP-928 benchmarks cited in an Ontario Energy Board filing — 92 % top-quartile scope stability). The $412,000 value of an outage day is the demo utility's own setting (energy $318,000 + water $94,000). Lumina Utilities, Harrowgate Bay Station, its contractors, people and records named on this page are fictional — characters and sample data in the working solution.
Software that builds and controls the scope and schedule of a planned unit outage — what work goes in, why, when it is done and what it does to the return-to-service date. Power Plant Outage Planning adds seven agents that build the scope from condition data, challenge work with no evidence and place each job on the critical path; the planner chooses and the outage manager signs.
Every scope item carries the evidence that justifies it: a condition reading within 36 months, a statutory rule, an OEM interval or bulletin. Items with none — a template carry-over, time-based only, a contractor proposal — are challenged with what was looked for and found, and a person keeps, splits or defers them. In the sample outage, 9 of 26 challenged items were deferred, taking 3.0 days out.
When the planner adds a finding, the scope builder drafts the job and the critical path scheduler places it on the network with its crew and shared resources, then recomputes the path and float. The header shows the new duration, return date and cost at once — in the sample case +2.0 days, return Wed 2 Dec, +$824,000.
The sequence advisor looks for a parallel way — a second crew or shift, prefabrication, different access or a different window — prices each in days and dollars and cites the past lesson behind it. It recommends one; the planner chooses. In the sample case prefabricated panels on nights held the outage at 28.0 days for $48,600.
Yes, if you set it. The value of an outage day is a setting used to price every option; at Harrowgate Bay it is $412,000 — replacement energy $318,000 plus $94,000 for water from the auxiliary boiler while desalination unit D4 runs on steam from another unit.
The readiness tracker watches milestones from T-180 to breaker open, work packages, materials by need date against ETA, contractor mobilisation, permits and clashes on shared resources such as the 40 t crane. The lessons matcher puts lessons from past outages against this outage's jobs. Neither places an order, books a contractor or marks a lesson applied.
Yes. The agents read, draft, challenge and propose; they never remove an item, pick an option, order material or change the approved baseline. The planner places work and chooses how, the plant engineer confirms the evidence, and every change after the freeze is signed by the outage manager.
The Agentic Solution Engine builds and deploys it from your requirements and documents — your outage procedures, evidence and challenge rules, scope templates, inspection reports and lessons registers — and it goes live once every quality gate has passed. We will walk you through it on one of your own past outages first.
Every trip explained, every repeat prevented.
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1-min demoWe'll run Power Plant Outage Planning on the scope, surveys and lessons of one of your past outages.