coupling-analysis

Map modules and their dependencies into a directed graph, then classify each dependency by integration strength, distance, and volatility. The balance formula STRENGTH × DISTANCE × VOLATILITY estimates maintenance effort for each coupled pair.

Model coupling occurs when an upstream module exposes its internal domain model directly, forcing consumers to know internal fields and types. Contract coupling uses dedicated integration DTOs designed for consumers, which is the weakest and preferred form.

Running git log over the last six months reveals which files change most frequently and which files change together. High co-change frequency indicates hidden functional coupling, while core subdomain files typically show the highest volatility.

Do not use it for domain boundary analysis or component sizing, which require different techniques. It also cannot detect dynamic connascence such as timing or identity without runtime observation, and organizational distance requires team context input.

Symmetric functional coupling is the same business logic duplicated across modules that must stay synchronized, even when the modules never reference each other in code. Static analysis tools generally miss it because detection requires semantic reading of the duplicated rules.