CH10-EX02. Case 2 — Nothing Confirmed Yet (Same Product)

• Related Chapter: CH10 (MODE A — Current Price Diagnosis)
• Related Tool: MODE A (core/engine/modes/mode_a.py, run_mode_a)
• Data source: docs/features/mode_a_current_price/CASE.md “Case 2 — same product, nothing confirmed yet” (fictional data, 04_incomplete_inputs.json)

Case Data

The same premium tumbler product, but price_includes_vat, vat_rate, the amount/rate of every cost item, and even fx.rate_base_per_reporting are all null (04_incomplete_inputs.json).

Think it through

As above, nothing apart from the price has been confirmed.

1. What does MODE A output when it runs on these inputs? (The module status and the status of the 7 metrics)
2. Why would it be dangerous to treat the unconfirmed costs as 0 and show a margin rate?

Show answer and walkthrough

What This Case Illustrates

The same product as EX01, but showing what MODE A outputs when none of the cost and tax data have been entered yet. It confirms CH10’s core design principle: MODE A honestly reports unconfirmed values as UNKNOWN rather than substituting 0.

Result

• mode_a.status = "INCOMPLETE"
• All 7 metrics are UNKNOWN
• 7 warnings — each metric specifies exactly which Client Input field is missing
• direct_cost_total and variable_cost_total each fail independently, due to different missing fields.
• gross_profit fails because both actual_price_ex_vat and direct_cost_total are unresolved (DOWNSTREAM_UNKNOWN). The metrics after it fail in a chain as a result.

Why This Case Matters

This case directly corrects a mistake made by the project’s prior (pre-Harness) prototype spreadsheet. That spreadsheet treated the same kind of missing cost as 0, and once reported a plausible-looking but baseless 81.5% margin. Case 2 shows what it looks like when, in the same situation, the engine honestly shows “what it doesn’t know.”