Most design reviews confirm a system will work. Almost none include a design review maintainability check — and that gap is expensive. When a maintainability problem is caught during design, it costs a drawing change. Caught during operations, the same problem costs 150 times more and compounds across every maintenance event for the life of the asset.
We caught one recently that made the point clearly.
Why Does Your Design Review Stop at Operational Readiness?
There’s a question that rarely makes it into a design review: after this gets built, can someone actually work on it?
Not “does it meet spec?” Not “will it pass inspection?” Those boxes get checked. The one that gets skipped is what happens when a maintenance crew shows up — not during construction, not at commissioning — but on a Tuesday, with a deadline. The design didn’t account for them. Now they’re working around it.
The scenario involves a mechanical piping assembly — bolted connections, valves, isolation components, vent stacks, and gauges that will need to be disassembled for routine maintenance. The design was correct. The system would have functioned exactly as intended. But when we walked through the future maintenance scenario — a crew actually removing the section of piping — problems emerged.
Clearances around the nuts and bolts weren’t enough. In some spots you could reach the bolt but couldn’t get the impact wrench on it to break the nut loose. Structural supports and valve bodies were positioned in a way that blocked access to the flange fasteners.
Everything fit. New piping. Valves that worked. Operationally, the project would have delivered. Maintenance would have been unnecessarily painful.
What Does a Maintainability Failure Actually Look Like in the Field?
A minor repositioning during design solved it. But that repositioning only happened because someone stopped and asked: when this needs to come apart, how does the crew do it? What are the tools? What’s in the way?
That question wasn’t in the design review checklist. It surfaced because someone was thinking past the build phase — running what we call the Virtual Impact Wrench Test: a deliberate walkthrough of each maintenance task as a physical sequence, before the drawings are final.
The fix was minor. But it only existed because the question got asked.
There’s a reason this matters beyond one piping assembly. The cost of finding a maintainability problem doesn’t stay flat — it multiplies the later you find it. This isn’t opinion. It’s a well-documented principle across every project type and industry.
| Project Phase | Cost of Change | The “Think Before You Build” Reality |
|---|---|---|
| Requirements / Design | 1x (Baseline) | The cheap fix. A drawing change, a repositioning, a question asked before anything gets built. This is where the Virtual Impact Wrench Test lives. |
| Construction / Build | 5x–20x | Now you’re cutting, reordering, and modifying work that’s already in the ground or on the wall. The crew is waiting. The schedule is bleeding. |
| Commissioning | 50x | The system is built and it can’t be safely operated or maintained as designed. Rework at this stage doesn’t just cost money — it costs credibility. |
| Operations | 150x+ | Operational Debt. The project “passed.” But for the next 30 years, every maintenance event costs more than it should have. Nobody connects it back to a design review that stopped too early. |
The scenario above was a 1x problem. It got caught at the design table. That’s the only place it’s cheap.
The Virtual Impact Wrench Test exists for one reason: to move discovery from the 150x column to the 1x column.
How Do You Run a Design Review Maintainability Check Before Drawings Are Final?
This is what cradle to grave thinking looks like in practice. Not a philosophy — a habit. The gap we see most often isn’t in the engineering. It’s in the failure to pressure-test the design against future use — to walk through the finished system as the person maintaining it, not the person who built it.
The project doesn’t end at turnover. The system will be maintained by people who weren’t in the design meetings, may not have the original drawings in front of them, and are working under pressure when something needs attention. Their experience is part of what gets delivered.
Before drawings are finalized, walk through the maintenance scenarios as an actual task sequence:
- Identify every component, system, or assembly in the project that will require periodic maintenance, inspection, or replacement over its service life
- Confirm the tools, equipment, access requirements, and clearances needed to perform each maintenance activity — including specialty equipment, manufacturer-certified technicians, and any lifting or rigging requirements
- Walk the completed design as the maintenance crew: verify that required tools and equipment can physically reach the work, that personnel can maneuver safely, and that access routes can accommodate everything the job demands — including getting it there in the first place
- If any maintenance task cannot be performed as designed, the design is not finished
The fix was minor. The habit is the hard part.
Think first. Execute strong.
Why is maintainability often missed in project design reviews?
Most design reviews focus on operational readiness — confirming a system works as intended — but skip the maintenance perspective. This results in systems that pass inspection but are unnecessarily expensive or difficult for crews to maintain over the asset’s life cycle.
How much does the cost of project changes increase over time?
The cost of change increases exponentially as a project progresses. Addressing a problem during design is the baseline (1x cost). That same problem costs 5x–20x during construction, 50x during commissioning, and over 150x once the project enters the operations phase.
How do you perform a maintainability check on a new design?
A maintainability check involves:
1) Identifying all components requiring periodic service.
2) Confirming the specific tools, equipment, access requirements, and clearances needed for each task — including specialty equipment, manufacturer-certified technicians, and any lifting or rigging requirements.
3) Walking the completed design as the maintenance crew to verify physical reach, maneuverability, and that access routes can accommodate everything the job demands.
4) Ensuring the design is not finalized until all maintenance tasks can be performed safely and efficiently.
What is the ‘Virtual Impact Wrench Test’?
The Virtual Impact Wrench Test is a deliberate walkthrough of each maintenance task as a physical sequence, conducted before drawings are final. The goal is to confirm that required tools and personnel can physically access, maneuver, and complete each task as designed — catching access and clearance failures at the 1x cost stage rather than after construction.
What is Operational Debt in construction project management?
Operational Debt is the compounding cost burden created when a project passes construction and commissioning but was never pressure-tested for maintainability. The asset functions as designed, but every routine maintenance event costs more than it should — often for decades — because access, clearance, and tool requirements were never validated during design.
