Normalize inputs
Check record keys, time zones, crew size, trip segments, and required timestamps before a rule is applied.
CASE STUDY 04 / RESEARCH TOOLS
Flight-duty screening and output validation
A traceable rules workflow with a separate check of the saved outputs.
3,198 RECORDS CHECKED
RULESCHECKREVIEW
Illustrative visual; no research data shownTHE QUESTION
How can configured duty-limit rules be applied consistently and checked against the source records?
THE SETTING
The screening workflow evaluates time-zone, crew-size, and multi-segment trip conditions. A separate validator recomputes selected expected fields and compares them with the exported audit results.
THE STORY IN PLAIN LANGUAGE
A successful export is the start of verification, not the end.
The workflow preserves the decisions behind a classification, then checks saved outputs through a separate reconciliation step. It demonstrates how data-quality logic, explicit boundaries, and an audit trail make a rules process reviewable.
Relevant perspectivesData engineer
Technology behind this workflow 9 tools & formats
The stack follows the analytical task: prepare the data, fit or apply the method, check the result, and communicate the output.
See how the libraries connect to the wider portfolio →THE PROJECT, STEP BY STEP
See how the question became a reviewable result.
04 / RESEARCH TOOLSVISUAL WALKTHROUGH
STEP 01 / 03Normalize inputs
Normalize recordEvaluate branchIndependent audit
3,198 records checkedSTEP 02 / 03Trace every branch
Normalize recordEvaluate branchIndependent audit
3,198 records checkedSTEP 03 / 03Reconcile independently
Normalize recordEvaluate branchIndependent audit
3,198 records checkedIllustrative process diagram
Trace every branch
Write intermediate audit fields with each screening result, separating clear outcomes from cases that need human review.
Reconcile independently
Compare saved outputs with recomputed values, record keys, and duplicate checks instead of trusting a successful export alone.
THE TECHNICAL CASE
Decisions behind the analysis.
A reliable rules workflow makes every decision traceable. The engineering value here is the separation of screening logic, audit fields, and an independent reconciliation of exported results.
- Unit of analysis
- A keyed flight record with crew, time-zone, segment, and required timestamp context.
- Inputs
- Source flight records and configured duty-limit rule inputs, including cases with incomplete or ambiguous fields.
- Deliverables
- Screening classifications, flagged records, audit workbooks, duplicate checks, and reconciliation summaries.
Normalize and validate inputs
The workflow handles time zones, crew-size branches, multi-segment trips, and acclimatization assumptions. Required keys and timestamps determine whether a record can be evaluated or needs review.
Make the branch inspectable
Intermediate fields explain how a final classification was reached. A flag without the values and rule branch that produced it is difficult to investigate, especially near a threshold or with incomplete timing information.
Validate the exported artifact
A separate script recomputes selected expected fields and compares them with saved outputs. This catches discrepancies in the delivered workbook rather than assuming that a script finishing successfully proves correctness.
Reconcile keys and duplicates
Record identity matters alongside numeric agreement. Reconciliation checks should establish whether the output contains the expected keys and whether duplicate records could change the reported counts.
METHOD IN FOCUS
Source record → normalize → evaluate branch → retain audit fields → independently reconcile
Agreement between an implementation and configured rules is a software-validation result. It does not independently certify the rules or their regulatory applicability.
EXPLORE THE METHOD
Follow an illustrative rule through its audit trail
This teaching example uses an invented 12-hour threshold. It is not an aviation duty-limit rule and must not be used for operational decisions.
QUALITY OF THE EVIDENCE
Checks that change the conclusion.
- Boundary values
Exercise a value just below, exactly at, and just above a configured threshold, and state the inequality used.
- Missing required inputs
Send unevaluable cases to review. Missing information should not silently become a pass.
- Independent computation
Compare saved outputs with a separately recomputed expectation and retain mismatch fields for investigation.
- Saved evidence
Reviewed workbook summaries contain 3,198 checked records and zero mismatches in the checked fields; the portfolio does not rerun the original pipeline.
FOR THE TECHNICAL CONVERSATION
Where I would take the discussion next.
A strong engineering discussion is how to prevent a validator from reproducing the same bug as the primary implementation, and how to retain enough audit context to explain an exception months later.
WHAT IT DEMONSTRATES
From method to meaning.
Saved validation summaries report 3,198 flight records checked and zero mismatches in the checked outputs.