Aerospace & Defense Manufacturing calculator
Material Substitution Review Gap Calculator
Track the remaining technical review for a proposed material substitution. Enter the required and completed evidence checks, expected review effort and available hours.
What this calculator does
- Count unresolved material substitution evidence checks and estimate the labor needed to close them.
Formula used
- Open checks = required evidence checks − completed evidence checks
- Remaining review hours = open checks × minutes per open check ÷ 60
- Review capacity headroom = available review hours − remaining review hours
Inputs explained
- Required Technical Evidence Checks: Checks established from the approved specification and proposed substitution.
- Completed Evidence Checks: Required checks completed with documented reviewer acceptance.
- Review Time per Open Check: Estimated labor to close one remaining evidence check.
- Available Review Hours: Labor hours assigned to the remaining technical review.
How to use the result
- Best suited to alternate material Review, engineering evidence planning.
- Check counts do not measure failure probability, consequence severity or material equivalence. Closing every check does not authorize a substitution or replace required engineering approval.
Current U.S. benchmarks
- Steel mill PPI stands at 381.162 (BLS, Aug 2026), up 23.4% from a year earlier. New factory orders are up 8.5% year over year (Census).
- The U.S. has 11,691 transportation equipment establishments employing about 1,682,910 workers (Census County Business Patterns, 2023).
Common questions
- Can this show that an alternate alloy is safe? No. Appropriate engineering analysis and evidence must establish suitability for the actual specification and service conditions.
- Who defines the required evidence checks? The responsible engineering authority defines them from the approved specification, proposed change and its technical consequences.
- Can I count a planned test as completed? No. Count it only after the required evidence is available and the reviewer accepts the check.
- Why is the result blank with no required checks? An empty scope cannot establish review progress. Define the required technical evidence before estimating the remaining work.
Last reviewed 2026-10-06.