Example Decision Record

Authoritative Decision Record

File Name: 04_Decision_Summary_and_Confidence.md

File Authority

This is an authoritative decision record.
It documents the outcome of the project and governs how the decision may be referenced or revisited.

This file does not reopen analysis. It records conclusions, confidence, and known limits.

Purpose of This File

This file exists to prevent post hoc rationalization. It captures the decision as it was made, including its confidence level and acknowledged uncertainties, so future review reflects reality rather than memory.

This file is the final control point in the project.

Decision Summary

Decision:
Proceed with purchasing a used or certified used mid-size sedan, prioritizing models with established reliability records over newer or higher-priced alternatives.

Decision Status:
Accepted

Intended Action Window:
Within the next six months.

Rationale (Condensed)

This decision reflects the following conclusions:

• Verified facts indicate substantial cost differences between new and used vehicles within the defined budget range.

• Reliability varies significantly by model and year, not by price or age alone.

• Warranty coverage shifts short-term repair risk but does not eliminate long-term uncertainty.

• Several commonly assumed signals (price, popularity, ratings) were found to be weak or misleading proxies for durability and suitability.

Trade-offs were explicitly acknowledged rather than optimized away.

This decision favors predictability and risk reduction over novelty or perceived value signaling.

Alternatives Considered

• New vehicle purchase:
  Rejected due to higher upfront cost without proportional reliability benefit.

• Lowest-cost used vehicle option:
  Rejected due to increased uncertainty around maintenance history.

• Certified used vehicle:
  Retained as a viable sub-option pending availability and verification.

Alternatives were not dismissed categorically; they were deprioritized based on documented constraints and assumptions.

Confidence Statement

Assigned Confidence Level:
Medium

Why Confidence Is Not High

Confidence is limited by the following unresolved or partially resolved factors:

• Model-specific maintenance cost data remains incomplete.

• Certified used vehicle availability may vary materially by location and timing.

• Long-term reliability projections beyond five years remain inherently uncertain.

These factors are documented and acknowledged. They were not overridden to force closure.

What Would Most Change This Decision

Any of the following would warrant re-evaluation:

• Credible, model-specific evidence indicating significantly higher maintenance costs than expected.

• Availability of a new vehicle option within budget that materially alters the cost–reliability trade-off.

• A documented change in usage requirements or ownership horizon.

Absent such changes, the decision remains stable.

Assumption Dependency Check

This decision depends primarily on the following assumptions:

• Reliability must be evaluated at the model-and-year level.

• Purchase cost should be weighted more heavily than resale speculation.

• Warranty coverage reduces short-term risk but does not define overall value.

All dependencies are logged in the Assumptions Log.

No unlogged assumptions were identified during final audit.

Audit Status

• Objective alignment: Confirmed

• Constraint compliance: Confirmed

• Evidence sourcing: Sufficient for medium confidence

• Alternative interpretations: Considered

• Premature closure: Not detected

Final audit result supports acceptance at medium confidence.

Closing Note

This decision is not a claim of correctness.
It is a record of disciplined judgment under uncertainty.

If revisited in the future, this file—not memory—defines what was known, what was assumed, and why the decision was made.

End of Project Example

You now have a complete, end-to-end, real-world demonstration of your methodology:

• Instructions

• File authority rules

• Objective definition

• Constraints

• Assumptions

• Facts vs inference

• Audit

• Decision & confidence

This is no longer abstract guidance.
It is a working system.

If you want next, I can help you:

• compress this example into a 10-page appendix, or

• write a “How to Adapt This Project to Other Domains” section, or

• design a template pack others can reuse without understanding everything at once.