A gas turbine hot gas path part does not wear out by the calendar. It wears with every start, every trip and every hour at high firing temperature. Yet many plants still track parts life in a spreadsheet kept by hand after each outage. With new gas turbines now quoted years out, a late parts order can be very costly. Gas turbine parts life tracking counts starts, equivalent hours and trips per serialized part, and shows when to order. Plan yours in a parts life review.
Gas Turbine Parts Life Tracking: Starts, EOH and Repairs
Consumed life calculated for every serialized part from the starts, trips and load your DCS already records, so planners see which limit governs each part and when the reorder window opens.
- Starts, trips and hours per serial number
- Repair cycles follow the part, not the unit
- Reorder alerts based on current lead times
Why Parts Life Is a Planning Problem Now
The equipment market is tight, and that changes how early you must plan.
Demand for gas-fired power has grown fast. In February 2026, Utility Dive reported Wood Mackenzie analysis that the average lead time for a new gas turbine in 2025 was almost five years from order, and a Jefferies note that large-frame makers were expected to be over 90% booked for 2028 and over 70% booked for 2029. GE Vernova, Siemens Energy and Mitsubishi Heavy Industries have all announced capacity expansions. When new units are scarce, existing units run harder and their parts matter more. Do not assume the part you need will be on a shelf. Our asset life specialists can review how your plant tracks parts today.
Parts life in a spreadsheet
- Counters typed in after each outage
- Trips counted as ordinary starts
- Life tied to the unit, not the part
- Orders placed when the outage is booked
Parts life tracked per serial
- Counters read from the DCS every day
- Trips weighted by load at the time
- Repair history follows each serial
- Orders placed when the window opens
Starts, Hours and EOH: Two Ways to Count Life
Manufacturers count wear in different ways. Your tracking must follow your OEM.
Gas turbine makers set inspection and parts intervals from operating hours and starts, adjusted for how hard the unit ran. A PJM education paper describes Equivalent Service Hours, where one hour equals one hour of base load operation without water or steam injection, and multipliers are added for starts, peak load, injection and trips. The same paper notes that GE's GER-3620 counts starts and hours separately: whichever limit is reached first sets the interval. Some other makers convert each start into equivalent operating hours instead, often called EOH. Map your OEM's method in a working session.
Factored hours
Fired hours weighted by load, fuel and injection.
Factored starts
Starts weighted by type, with trips counted extra.
Equivalent hours
Starts and trips turned into hours and added up.
First to reach
Under a dual count, the first limit governs.
Summary for orientation only. Your OEM's documents and service agreement set the method and limits for your units.
What Uses Up Parts Life Faster
Not every hour or start is equal. The factors are where the real wear shows.
The factors that raise consumed life are well known, even though their values differ by OEM and model. A Combined Cycle Journal article on GER-3620 notes that each hour at peak firing temperature, about 100°F over base load, counts as six hours for hot gas path parts. Trips are the next big one. A 2021 paper by Thielmann describes a trip severity factor that rises with the load at the moment of the trip, using parameters set by the manufacturer. Fuel type and water or steam injection add their own factors. Agree your factor sources with our engineering team.
Worked Example: Consumed Life for One Serialized Part
One set of stage 1 buckets, counted both ways since its last repair.
This example uses round, illustrative factors so the method is easy to follow. A real calculation uses the factors and limits in your OEM's documents. The set in the example has an interval of 24,000 factored hours or 900 factored starts. Normal starts count as one, fast starts as two and full-load trips as eight. Peak hours count as six. The set has had one repair already. Walk through your own parts in a short session.
Starts govern here, even though the unit has run many hours. At about 30 factored starts a month, the 502 starts left last about 17 months. At about 600 factored hours a month, the 13,900 hours left would last about 23 months. If the quoted lead time for a replacement set is 14 months and the plant adds two months for receiving inspection, the reorder window is already open.
All figures illustrative. Factors, limits and lead times vary by OEM, model and part.
See Consumed Life for Every Serialized Part
Starts, trips and load read from your DCS, factors applied per part, the governing limit shown and planners alerted the moment a reorder window opens.
Tracking Parts Across Repair Cycles
A part's life belongs to its serial number, wherever it goes.
Hot gas path parts are often removed, repaired and reused for more than one interval. A set of buckets may run in Unit 2, go to a repair shop, sit in stores and then go into Unit 4. Tracking by unit loses that history at every swap. Tracking by serial keeps the counters, repair reports and findings with the part. It also shows the repair count, which matters because each part type can take only so many repair cycles, as set by the OEM or repair vendor. Ask our team how serial history is set up.
Install
Serial linked to unit and position.
Run
Starts, trips and hours counted.
Remove
Counters closed at the outage.
Repair
Shop report and repair count added.
Reuse or retire
Back to stores or scrapped.
Setting Reorder Windows from Lead Times
The window opens when remaining life meets lead time plus buffer.
A reorder window is simple arithmetic once the inputs are right. Take the remaining life of the governing limit, divide it by the recent rate of use, and compare the result with the current lead time for the part plus a buffer for shipping, receiving inspection and outage planning. Keeping the inputs current is the hard part, as a trip or two can move the date by months. The AI watches all three and tells the planner when a window opens or moves. Planners still decide whether to buy new, repair or use a spare. See it working in a live demo.
Reading Starts, Trips and Load from the DCS
The counters already exist. They just need to reach the part record.
The turbine control system already records most of what parts life needs: start events and start mode, fired hours, load, firing temperature mode, fuel mode, injection and trips. The one step that needs care is trip classification. A trip at low load and a trip at full load wear parts very differently, so each trip must carry the load at the moment it happened. Review your signal list with our controls engineers.
Start events
Normal, fast or emergency mode and ramp time.
Fired hours
Hours with flame, split by load band.
Trip log
Each trip with the load at the time.
Peak mode
Hours above base firing temperature.
Fuel mode
Gas, liquid or dual fuel hours.
Water or steam
Injection flow and hours.
Gas Turbine Parts Life Tracking Checklist
Eight checks before parts life tracking goes live.
Use this checklist for one unit first. Tick items already in place. Get help with any gaps from our setup team.
Parts Life Tracking Mistakes to Avoid
A count that looks fine on paper can hide a part near its limit.
These are the patterns that most often weaken gas turbine parts life programs. A short parts life review can find them.
What works
- Life tracked per serial number
- Both limits checked, the first one governs
- Trips weighted by load at the time
- Lead times reviewed with each new quote
What fails
- Only fired hours counted
- Trips logged as normal starts
- Repair count lost when parts move
- Old lead times left in the plan
How iFactory Tracks Gas Turbine Parts Life
The Asset Life Agent, on your own network.
iFactory's Asset Life Agent reads starts, trips and load from the DCS, calculates consumed life per serialized part and alerts planners when reorder windows open given current OEM lead times. It runs on an on-prem AI server inside your plant.
DCS counters
Starts, trips and load read directly.
Per serial
Life follows each part across units.
Consumed life
Factored hours and starts per part.
Repair history
Shop reports and repair counts kept.
Lead times
Quotes recorded with their dates.
Reorder alerts
Planners told when windows open.
Purchasing, repair and outage decisions remain with your planners and engineers. Figures on this page are worked examples.
Turnkey AI: Delivered, Connected and Live in 6–12 Weeks
You do not build this. It arrives ready.
iFactory ships as a pre-configured NVIDIA AI server with the software pre-loaded, racked and ready. Rack it, plug in power and Ethernet, and the AI is live on your network. Our team handles cabling, network setup, PLC, SCADA, DCS and CMMS integration, OEM factor set-up and parts register loading, operator training and 24×7 remote monitoring. Data stays on your network. For a scope matched to your plant, request a turnkey quote.
Ship, network and data
Server installed. DCS start, trip and load signals connected. Parts register loaded by serial.
Model training and pilot
OEM factors and limits set per part type. Consumed life checked against your outage records.
Go-live and training
Parts life live. Planners trained on reorder windows. 24×7 monitoring begins.
Frequently Asked Questions
What is gas turbine parts life tracking?
Counting the starts, trips and weighted hours each serialized part has seen, so its consumed life and next action are known at any time.
What are equivalent operating hours?
A way to express mixed operation as one figure, adding extra hours for starts, trips, peak load and other harder duty, using factors set by the OEM.
What are factored fired starts?
Starts weighted by type. A fast start or a trip from high load counts as more than one normal start.
Which limit governs, starts or hours?
Under a dual count such as GE's, whichever limit is reached first. Cycling units are often starts-limited, base load units hours-limited.
Why track by serial number?
Parts move between units, shops and stores. Tracking by serial keeps their counters and repair history with them.
Where do the factors come from?
From your OEM's documents and service agreement. The system records the source of each factor so engineers can check it.
Does the AI order parts?
No. It flags when a reorder window opens and shows why. Planners decide whether to buy, repair or use a spare.
Does this replace our CMMS?
No. Work orders and stores stay in your CMMS. The agent adds consumed life and reorder alerts to the part record.
How do we start?
Start with one unit and its hot gas path and combustion parts. A 6-week pilot connects the DCS and loads the parts register. To plan it, contact our team.
Order Long-Lead Turbine Parts on Time
In thirty minutes we take one unit's operating history and show consumed life per part, which limit governs and which reorder windows are already open. You keep the results either way.
- 1Your parts register with serials
- 2Starts, hours and trip counts since the last HGP
- 3OEM maintenance factor documents
- 4Recent repair shop reports
- 5Current lead time quotes
