Best Feasible Alternative Test¶
Decision rule — instantiates Feasible-Alternative Comparator Calibration
Applies the rule that an option is validly rejected only if some feasible alternative beats it on net — not because it falls short of an ideal.
Everything else in this archetype prepares the ground; Best Feasible Alternative Test is the rule that renders the verdict. It states one condition and holds the decision to it: an option may be rejected only if there exists a feasible alternative with a higher net value under the same constraints. It searches the feasible set for the best available rival — the operative comparator — and asks whether that rival actually beats the option on balance. If none does, the option stands, however imperfect. Its defining act is quantifying rejection over the feasible set rather than against an ideal: "this has flaws" is never sufficient; "this is beaten by that reachable alternative" is. It does not build the option set or score the grid; it consumes them and pronounces go, keep, or replace.
Example¶
A team is hiring a new engineering lead. The strongest candidate in the finalist pool is excellent technically but a mediocre public communicator, and the hiring committee is drifting toward rejecting them because "a great lead should be strong at both." The test intervenes with its rule. It scans the feasible set — the actual finalists who would accept the role at the offered level — for the best available alternative to this candidate. The next-best finalist communicates well but is materially weaker technically and on team trust. On net, across the dimensions that matter for this role, no feasible alternative beats the top candidate.
So the rule speaks: the objection describes a real defect but names no feasible alternative that dominates. The imagined "strong-at-both" lead is not in the pool and, at this level and timeline, cannot be conjured into it. The committee's valid choices collapse to two: hire the top candidate and coach the communication gap, or reopen the search accepting its cost and delay. What it may not do is reject the best feasible option for failing to be the ideal one — because rejection, under this rule, requires a better real alternative, and there isn't one.
How it works¶
- Identify the operative comparator. From the feasible set, select the best available alternative to the option under review — the one with the highest net value on the shared dimensions.
- Run the net comparison. Weigh the option against that comparator on balance, letting strengths offset weaknesses rather than letting any single flaw be decisive.
- Apply the rejection condition. Reject only if the comparator wins on net; otherwise the option stands as at least as good as anything reachable.
- Name the deciding margin. Report which alternative and which dimensions carried the verdict, so the decision hangs on a real rivalry, not a general dissatisfaction.
Tuning parameters¶
- Net-value aggregation — how strengths and weaknesses are combined (weighted sum, threshold-gated, dominance-only). Compensatory aggregation lets a strong option survive one weak dimension; stricter rules do not.
- Margin of victory required — how much a comparator must beat the option by to justify switching. A near-tie usually favors the incumbent option unless the rival clearly dominates.
- Comparator scope — whether "feasible" is judged now or after reasonable effort to expand the set. Widening it can surface a better rival but delays the call.
- Tie-break rule — what happens when no alternative dominates: default to the option under review, to the status quo, or to reopening the search.
When it helps, and when it misleads¶
Its strength is decisiveness with discipline: it converts endless "but it's not perfect" objections into a single answerable question — what feasible alternative beats it? — and refuses to reject on flaws alone. It is the operational form of the maxim that the perfect must not be made the enemy of the good.[1]
Its failure mode is a hollow feasible set or a stacked comparison. If the option roster is thin or a genuinely reachable alternative was never enumerated, the rule can bless a weak option simply because nothing better made the list — the test is only as honest as the set it searches. It can also be gamed by picking a deliberately weak comparator so the favored option "wins on net." The guarding discipline is to run the rule only over a fair, well-scoped set, to insist the comparator be the best feasible rival rather than a convenient one, and to revisit the verdict if a stronger reachable alternative later appears.
How it implements the components¶
Best Feasible Alternative Test fills the decision-rule components — the ones that turn a scored field into a verdict:
best_feasible_comparator— it selects the highest-net-value reachable alternative as the operative baseline the option must be judged against.feasible_option_set— it quantifies the rejection condition over that set (∃ a feasible alternative that beats the option), consuming the roster to bound the search.
It does not build the scored field it reads from — that is Shared-Burden Comparison Table's shared_dimension_scorecard — nor does it stress-test whether its verdict survives changed assumptions (dominance_and_sensitivity_matrix, Feasibility Sensitivity Probe). It reads the field and rules; robustness is checked after.
Related¶
- Instantiates: Feasible-Alternative Comparator Calibration — this rule is the archetype's decisive move: reject only against a dominating feasible alternative.
- Consumes: Shared-Burden Comparison Table supplies the scored dimensions the net comparison reads.
- Sibling mechanisms: Feasible Option Inventory · Ideal Comparator Filter · Status Quo Costing Sheet · Shared-Burden Comparison Table · Defect/Disqualifier Sort · Comparison-Class Review Memo · Feasibility Sensitivity Probe
Editorial Notes¶
Form Classification¶
Form family: Rule, Policy & Commitment
Rationale: The mechanism imposes the standing rejection condition that an option may be rejected only when a feasible comparator beats it on net, so its operative form is a decision rule.
Nearest alternative: Decision, Gate & Allocation — Applying the test yields a case disposition, but the same precommitted comparator condition governs every future disposition.
Review outcome: Adjudicated after independent review; high confidence.
Origin Attribution¶
Primary origin: Economics & Finance
Origin pattern: Convergent development
Present-day reach: Universal
Rationale: Economics evaluates choice through trade-offs, opportunity cost, and the value of the best available alternative under scarcity rather than an unattainable ideal.
Related originating lineages:
- Operations Research — Constrained optimization supplies the feasible set and maximization over reachable options.
- Philosophy — Practical reason and satisficing reject comparison with impossible ideals and require action-relevant alternatives.
Review resolution: The Federal Reserve defines opportunity cost as the value of the next-best alternative, and GAO guidance requires identifying feasible alternatives, comparing their costs and benefits on common terms, and selecting the greatest net benefit within constraints. That directly matches this test's comparator and rejection condition. Operations research formalizes the feasible-set optimization, while philosophy supplies the anti-ideal norm.
Attribution caveat: The page turns the economic comparator into a universal rejection rule and depends on honest construction of the feasible set.
Review outcome: Researched adjudication after independent review; high confidence.
Sources consulted:
- Federal Reserve Bank of St. Louis — Opportunity Cost and the Next-Best Alternative
- U.S. GAO — Surface Transportation: Many Factors Affect Investment Decisions
- U.S. GAO — Analysis of Alternatives Best Practices
References¶
[1] Voltaire. La Bégueule (1772). States Voltaire's maxim that the best is the enemy of the good. registry ↩