Report the surviving blade's observed service and remaining condition at the cutoff, and keep its final life unresolved. You can compare recorded performance and costs over the defined trial period, but you cannot convert an unfinished service interval into a guaranteed wear-out life. State which decision the incomplete evidence can support and which one needs further observation.
Record exposure and remaining condition at the cutoff date
Record the trial end date, actual service exposure and reason observation stopped. Distinguish a scheduled study cutoff from removal because of condition, incident or another maintenance need. Identify the blade and configuration and preserve the last qualified condition assessment. If the blade remains installed, note that its service continues beyond the reporting period rather than entering an artificial removal date to satisfy the spreadsheet.
Use the blade-lifespan background to frame the variables, while keeping this report tied to the observed interval. Record the remaining condition with the same method used earlier so the final inspection is interpretable. A photograph can supplement that record but should not be converted into an unmeasured life estimate. Include missing exposure or inspection information, because a precise cutoff date does not make the rest of the observation complete.
Separate observed costs from unobserved future life
Separate the cost question from the lifespan question. A period-cost report can include the actual costs and service output during the study under a consistent accounting method. A lifetime-cost claim requires assumptions about unobserved future service, later changeovers and other events. If projections are useful for planning, show them as scenarios and identify the inputs that could change the conclusion. Do not merge projected savings into the observed result without distinction.
Check that the comparison treats starting and ending inventory consistently. One blade may have consumed its available service during the trial while another retains an assessed residual condition. That difference is relevant, but the fleet's method for representing it should be explicit and consistently applied. Avoid giving the unfinished option an optimistic remaining-life value while charging the completed option all its actual costs. Ask the responsible financial and technical owners to agree the interpretation before presenting a single ranking.
Present the result as incomplete rather than extrapolating a guaranteed final lifespan
Use clear outcome language: the candidate completed the observed exposure without reaching the recorded replacement condition, while its eventual endpoint remains unknown. Keep service-quality findings separate so longer observed retention is not mistaken for acceptable clearing performance. If the other blade was replaced for a different reason, disclose that too; the two endpoints may not represent the same event.
For a continued blade evaluation, decide whether additional observation can answer the unresolved question under normal operations. Preserve the original trial definition and record any changed route, equipment or season conditions during follow-on service. If continuation is impractical, close the study as incomplete for final lifespan rather than forcing an estimate. The result can still inform procurement, provided the decision record identifies the evidence actually obtained and does not present an unobserved endpoint as a measured advantage.
Further reading. Clear Roads evaluation ↗
