Structured Business Logic Injection for LLM-Based Code Generation: What a Design Document Must Carry
Large language models generate code effectively but falter in enterprise settings that demand complex business rules, particularly in rule consistency and conflict detection. This study proposes the Atomic Logic Sheet (ALS), a structured representation of business logic, injected through the Hierarchical Business Logic Injection (H-BLI) framework. Four conditions were compared on a warehouse management domain, 20 runs each: requirements only; a natural-language design document; the same content with worked examples, anti-patterns, and an explicit conflict-handling directive in prose; and that content expressed in ALS. Conflict responses were adjudicated by two independent raters (κ = 0.993 and 1.000) and cross-checked against a byte-level code comparison. Logic compliance converged near 97% whenever a design document was supplied; conflict detection separated them: 10.0% and 43.1% for the requirements-only and plain-document conditions, and 100% for both content-bearing conditions, neither of which modified code. The two notations detected conflicts identically, and where they differed, the prose condition was better, so the effect follows the content a document is obliged to carry rather than its notation. A replication under a second model reproduced the gap between the requirements-only baseline and the full treatment, and a replication on independently designed conflicts reproduced the detection result for the document conditions; neither included the prose condition, so neither reproduces the comparison between notations. Schema deviation, however, was higher under ALS. As a single-domain study, replication elsewhere remains necessary.