A sound shutdown-cost case defines the event, time boundary and operating scenario before listing costs. Include process interruption, controlled depressurising, site resources, valve work, restart and follow-up. Keep every assumption visible, and never present avoided cost as guaranteed savings.
Knowledge · Maintenance decisions
Building a shutdown-cost case for valve work: cost categories, boundaries and assumptions
A practical structure for comparing valve work without invented savings or false precision.
1. Define the shutdown event before counting costs
The word shutdown can describe very different operating events. A local isolation, unit outage and network interruption do not share one cost boundary.
State which assets stop, which continue and which customers or processes are affected. Record the start point, return-to-service point and any reduced-capacity period.
Also define the comparison. The case may compare planned replacement, shutdown repair or suitable online valve maintenance. It should not compare unrelated scopes.
2. Use complete cost categories
Each site should fill these categories with its own approved operational and financial data. Do not import figures from another facility.
- Production and delivery. Record interrupted output, reduced throughput, product movement and customer supply effects.
- Process preparation. Include controlled isolation, depressurising, draining, purging, venting or flaring where applicable.
- Site resources. Include operations, maintenance, safety, inspection, permits, access, lifting and contractor coordination.
- Valve work. Include parts, replacement valves, consumables, tools, workshop tasks, transport and waste handling.
- Restart and acceptance. Include testing, line preparation, controlled restart, monitoring and correction of start-up issues.
- Follow-up. Include records, inspections, later tests and any temporary measures that remain after work.
Flaring and venting belong only where the operating plan requires them. Their inclusion must follow the site's measured or approved estimating method.
3. Mark boundaries and assumptions clearly
A useful case separates known inputs, estimates and exclusions. This prevents a precise-looking total from hiding weak evidence.
- Identify the owner and source for every operational input.
- State whether durations come from a plan, past event or engineering estimate.
- Separate fixed task costs from time-dependent operating effects.
- Show which costs occur under both options and which differ.
- Record exclusions, dependencies and the consequence if assumptions fail.
Use ranges or scenarios where the duration is uncertain. Do not turn the highest possible interruption into the expected case.
The repair-versus-replacement guide explains how these boundaries fit the wider valve decision.
4. Test whether online work is actually available
Avoided shutdown categories matter only when online work passes its engineering gates. The valve needs suitable injection fittings in good condition.
The design and service must suit the cleaner, lubricant or sealant. OEM guidance applies, equipment ratings remain binding, and operations must permit the work.
Confirm the fault before selecting treatment. Pressure rise, flow indication or noise may suggest seat leakage, but an accepted test must confirm it.
Severe mechanical damage, broken parts or unsuitable fittings can remove the online option. See online repair limits before claiming any avoided event.
5. Present the case as a decision, not a promise
Show at least the planned case and a credible adverse case. Explain which assumptions change the result and who owns them.
Do not label every shutdown category as a saving. Some costs may be deferred rather than removed, especially when temporary sealing supports later planned repair.
Include condition, risk and endpoint beside the economics. A cheaper option that cannot deliver the required isolation is not an acceptable option.
Link the decision to the network maintenance budget and record the next review trigger. BTR VSI valve surveys and field services can provide condition evidence, but the operator owns shutdown assumptions.
Common questions
Shutdown-cost questions, answered directly
What belongs in a valve shutdown-cost case?
Include operating interruption, process preparation, site resources, valve work, restart, acceptance and follow-up. Use the facility’s own approved data for every cost input.
Can avoided shutdown cost be called a saving?
Not automatically. Some work may be deferred rather than removed, especially after temporary treatment. Describe avoided, shifted and remaining categories separately.
How should uncertainty be shown?
Separate known inputs from estimates and exclusions. Use clear scenarios when duration or operating effect is uncertain, and record who owns each assumption.
When is online work a valid comparison?
Only when the valve, service, fittings and operations permit it. Confirm the fault first, follow OEM guidance and keep every equipment and fitting rating binding.
Building a shutdown case?
Send the valve scope. An engineer replies within 24 hours.
Include the fault evidence, affected assets, operating boundary and planned work route.