STD: Negative Control Inhibition Rule (BICQUAL)

Version: v1.0.0 Status: Draft SRS Source: docusaurus/docs/srs/rules/rule-negative-control-inhibition.md Rule Name: BICQUAL Domain: RULES-NECINH

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Overview

This document specifies tests for the Negative Control Inhibition rule (BICQUAL) using decision tables and test vectors. The rule detects inhibition in Negative Extraction Control (NEC) wells by evaluating Internal Control (IC) amplification results and generates appropriate error codes when inhibition is detected.

Rule Characteristics:

• Pure business logic (no UI)
• Simple threshold evaluation (CT > 35)
• Classification-based fallback (Negative with null CT)
• Dual error output (well-level and run-target-level)

Test Method: TM-API (per Test Plan §3.3 - Rules use automated API tests)

Verification Approach: Rule verification is performed using data-driven test vectors. Each row in a decision table represents a complete verification scenario with defined inputs and expected outputs. This format enables exhaustive condition coverage while remaining concise and auditable.

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Coverage Summary

REQ ID	Title	Conditions	Test Vectors	Coverage	Gaps
REQ-RULES-NECINH-001	Detect Inhibition in NEC Wells	8	10	100%	None

Totals: 1 REQ, 8 Conditions, 10 Test Vectors, 100% Coverage

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REQ-RULES-NECINH-001: Detect Inhibition in NEC Wells

Input Variables

Variable	Type	Valid Values	Description
well.type	string	NEC, PEC, Patient, ...	Well control type
obs.ic_ct	float?	null, numeric (0-50)	IC target CT value
obs.ic_cls	string	Positive, Negative	IC target final classification

Output Variables

Variable	Type	Description
well.error_code	string?	BIQUAL_WELL or null
run_target.error_code	string?	BICQUAL_TARGET or null

Constants

Constant	Value	Description
IC_CT_THRESHOLD	35	CT threshold above which IC amplification is considered inhibited

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Decision Table: Well Type Filter

TV	well.type	rule_triggered	Covers
TV-001-001	NEC	true	AC: Rule triggers on NEC wells
TV-001-002	PEC	false	AC: Rule skips non-NEC wells
TV-001-003	Patient	false	AC: Rule skips non-NEC wells

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Decision Table: CT Threshold Evaluation

TV	obs.ic_ct	obs.ic_cls	well.error_code	run_target.error_code	Covers
TV-001-004	25.0	Positive	null	null	AC: Normal IC (CT << 35)
TV-001-005	35.0	Positive	null	null	AC: Boundary (CT = 35 exactly, no error)
TV-001-006	36.0	Positive	BIQUAL_WELL	BICQUAL_TARGET	AC: Inhibited (CT > 35)
TV-001-007	45.0	Positive	BIQUAL_WELL	BICQUAL_TARGET	AC: Late IC (CT >> 35)

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Decision Table: Negative Classification Handling

TV	obs.ic_ct	obs.ic_cls	well.error_code	run_target.error_code	Covers
TV-001-008	null	Negative	BIQUAL_WELL	BICQUAL_TARGET	AC: Negative classification with null CT
TV-001-009	null	Positive	null	null	AC: Null CT with Positive classification (edge case)

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Decision Table: Combined Conditions

TV	obs.ic_ct	obs.ic_cls	well.error_code	run_target.error_code	Covers
TV-001-010	35.0	Negative	BIQUAL_WELL	BICQUAL_TARGET	AC: Boundary CT with Negative classification

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Boundary Value Analysis

Boundary	Below	At	Above	Covers
CT = 35	TV-001-004 (CT=25)	TV-001-005 (CT=35)	TV-001-006 (CT=36)	Threshold behavior

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Error Code Verification

TV	Error Type	Expected Code	Prefix Validation	Covers
TV-001-006	Well Error	BIQUAL_WELL	BIQUAL (single I)	AC: Well error uses BIQUAL prefix
TV-001-006	Run Target Error	BICQUAL_TARGET	BICQUAL (with IC)	AC: Run target error uses BICQUAL prefix

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Traceability to Existing Tests

Requirement	Jira Tests	Automation Status
REQ-RULES-NECINH-001	BT-5175	Automated (2 TVs)
REQ-RULES-NECINH-001	BT-1315, BT-1318, BT-1338, BT-1340, BT-1138, BT-1141, BT-1164, BT-2786	Manual (8 TVs)

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Gap Analysis

Identified Gaps

Gap	Requirement	Description	Priority	Owner
None	-	All test vectors covered by existing automation	-	-

Coverage Notes

• All acceptance criteria from SRS are covered by test vectors
• Boundary value at CT=35 explicitly tested (TV-001-005)
• Error code prefix validation included
• Both well-level and run-target-level outputs verified