Practical feasibility: weighted facility review and retained research limits

9 October 2026. The first product remains facility-planning assurance. The preceding feasibility record preserves source-parameter calculations, narrow-model distinctions and conventional-library comparisons across the other opportunities. No source backend was promoted or proof accepted in this edition.

New ordinary assignment checker

The weighted rectangular module now checks exact submitted costs, whole-client assignments, mandatory openings and capacities. It accepts exactly-k or at-most-k selection with stable independent client/site namespaces. A capacity control shows why nearest-site reassignment cannot be accepted without checking loads. Required sites need not have positive load or be filled.

Input caps are 512 clients/128 sites, eight MiB/file, sixteen MiB combined and 128-bit rational input components. Optional conventional solver scales are exact and capped at one million, with conservative integer limits of 2^60, two seconds and one worker. These are explicit domain/solver bounds, not memory or total-runtime guarantees. Additional business constraints are refused rather than omitted. Geographic distances and physical measurements are not validated by arithmetic checks.

The exact relaxed lower bound drops opening, capacity and mandatory-site restrictions. Difference from a checked cost bounds suboptimality from above; it is not a measured actual optimum gap. A solver OPTIMAL/INFEASIBLE status remains a solver report. Only equality with the independent lower bound proves optimality in this module. The original strict-metric reference retains its own enumeration/dual contract, and no new source theorem is applied to weights/capacities.

Evidence and remaining work

7,952 new controls include a complete 7,776-model grid containing 93,312 submitted plans, plus eleven recorded solver/export examples and intake/display boundaries. A self-authored 100-client/10-site case has checked cost 2373, bound 2260 and submitted cost 5472. The numbers are synthetic objective units. They do not establish speed superiority, actual savings, formal program correctness or a profitable market.

Local browser intake, stronger weighted/capacity certificates and permissioned study evaluations remain useful next work. Production hosted jobs, accounts and data handling have not been deployed. Fixed costs, fairness, splitting, time windows, multiple demand types, utilization minima and uncertainty require new contracts before support can be claimed.

The product plan retains an unvalidated AUD 5,000-10,000 assisted-review experiment. Buyer demand and delivery economics remain unknown. Complete current utility list: 38 utilities, 29,805 passed checks in 60 saved reports. Reading ledger: unchanged 42 selected-section records and 105 source hashes, with full source/proof acceptance incomplete.