The Concurrent Attrition Tax

The Congressional Budget Office's December 2025 report confirmed what every dry dock superintendent already knew. Navy ship maintenance events are running 20 to 100 percent over their estimated durations.¹ But the CBO data describes a symptom. The disease is how prime contractor project managers treat the dry dock schedule as a flexible container for concurrent work, stacking trades on top of each other under the assumption that parallel activity equals efficiency.

It does not. It creates the Concurrent Attrition Tax.

What the Tax Looks Like Inside the Hull

Every major availability tells the same story. The prime contractor, staring down a compressed schedule and liquidated damages, decides the electrical team can pull cable in the same compartment where the hot work crew is welding out structural modifications. The logic on the spreadsheet is clean. The reality inside the hull is predictable.

When you stack electrical installation on top of active structural and mechanical work, you are not saving time. You are guaranteeing rework. The physical damage from ongoing structural activity compromises the integrity of newly installed cable runs. The interference from adjacent work violates the sequencing requirements that MIL-STD-461G and MIL-STD-1399 are built around.²³ When a welder burns through a newly pulled shielded cable because the schedule demanded both trades occupy the same ten-foot space, the cost is not just the replacement cable. It is the time to rip out the damaged run, re-pull it, and re-test it.

That is the Concurrent Attrition Tax. And you are collecting it from your own project.

The CBO Put Numbers to What the Deck Plates Already Knew

DDG-51 class destroyers are projected to spend an average of nine years, more than a quarter of their planned service life, out of the fleet for maintenance.¹ Labor overruns for these events exceed estimates by 8 to 40 percent depending on the event type.¹ The longest overhauls, the DMPs and EDSRAs that involve the most modernization and the most extensive electrical scope, show the worst performance, averaging 29 percent over the final schedule estimate.¹

These are not random failures. They are the predictable output of a scheduling philosophy that treats skilled electrical work as a contingency buffer for structural delays.

NAVSEA Standard Item 009-73 exists precisely because the sequencing of electrical cable work relative to other trades is a documented, recurring failure point in ship availabilities.⁴ Treating it as a scheduling inconvenience rather than a technical requirement is how a 90-day SRA becomes a 120-day SRA.

Why the Tax Keeps Compounding

The Concurrent Attrition Tax compounds across availabilities because the cost of each rework event is absorbed within the availability that produced it, not tracked across the industrial base. The prime contractor negotiates the change order, recovers the cost through the Change Order Economy, closes the availability, and moves to the next contract. The attrition cost, however, does not close.

The Concurrent Attrition Tax is paid in three currencies. The first is direct labor rework cost, which the change order recovers. The second is workforce attrition, which no change order recovers. The third is the accumulated erosion of technical competence in the industrial base, which no mechanism currently tracks.

A marine electrician who spends a compressed availability doing damaged-cable rework instead of clean new installations is the electrician who takes a commercial job next quarter. The McKinsey January 2026 report on the maritime workforce documented the pattern. Shipyards often lose their trained staff to other fields precisely because the high-pressure, chaotic work environment of concurrent availabilities drives attrition.⁵ The Concurrent Attrition Tax is the mechanism that produces the attrition. The attrition is the mechanism that produces the next availability's capability gap.

What the Sequence Actually Requires

The alternative to concurrent stacking is sequential execution with rigorous trade handoff. Structural work completes in a compartment before electrical work begins. Electrical installation completes before mechanical insulation and finishing. Each trade exits the compartment clean, with documented completion, before the next trade enters.

This is the sequence that commercial maritime construction uses. It is the sequence that shipbuilders like Royal Caribbean's Oasis-class construction uses. It is not an exotic approach. It is the approach the commercial maritime world has used for decades because concurrent stacking produces the Concurrent Attrition Tax that commercial economics will not absorb.

The Navy's industrial base is absorbing the Concurrent Attrition Tax because the Change Order Economy makes the absorption profitable for primes, the QAR Vacuum makes the rework invisible to government oversight, and the procurement system rewards the bid that accepts the concurrent schedule over the bid that prices sequential execution accurately. The structural incentives produce the tax. The tax produces the overrun. The overrun becomes the new baseline. The cycle continues.

Closing the Tax

The Concurrent Attrition Tax cannot be eliminated through contractor exhortation. The tax is the cost of a scheduling philosophy that the procurement system rewards. Eliminating the tax requires eliminating the reward.

That means contract structures that price sequential execution as the baseline and treat concurrent execution as an exception requiring documented justification. It means program offices that recognize the CBO's 20 to 100 percent overrun data as the empirical consequence of the concurrent scheduling default, not as random variance around a stable mean. It means primes that build project management capabilities around sequential trade handoff rather than concurrent deconfliction.

Prime contractor project managers and NAVSEA program office leadership: review the last three availabilities your organization executed. How many trades were in the same compartment simultaneously during electrical installation? If the answer is more than one for any significant percentage of the electrical scope, your organization is paying the Concurrent Attrition Tax, and the CBO's overrun data is telling you the size of the payment.