Weakened Modularity

Description

Each module must strive for high cohesion and low coupling. This smell arises when a module exhibits high coupling and low cohesion.

Context

Derived from: “Weakened Modularity”
High cohesion is one of the most important design principles. Modules should provide operations that are closely related to each other. Functionality that is likely to change together should be in the same artifact.

Cause

Often these divergent modifications are due to poor program structure.

Consequences

The maintainability and possibility for development may be reduced. It may be more difficult to analyze and grasp all provided functionality.

Detection

We compute the modularity ratio for each module by dividing the number of intra-cluster references (cohesion) and the number of inter-cluster references (coupling). To ensure that elements without internal relations modelled are not reported a minimal internal relation count has to be reached.

Solution

Split up the behavior of the module.

Cypher query

MATCH (a)-[r]-(b) <br /> WHERE (r.Label contains 'Aggregation' or r.Label contains 'Realization' or r.Label contains 'Composition' or r.Label contains 'Assignment') <br /> and a.ArchimateLayer = b.ArchimateLayer <br /> WITH a , collect (r) as rels , a+ collect (b) as cluster <br /> MATCH (m)-[r1]->(n) <br /> WHERE not (r1.Label contains 'Aggregation' or r1.Label contains 'Realization' or <br /> r1.Label contains 'Composition' or r1.Label contains 'Assignment') and <br /> (m in cluster and not n in cluster) <br /> WITH a , cluster, collect (r1) as internal <br /> MATCH (m)-[r2]->(n) <br /> WHERE not (r2.Label contains 'Aggregation' or r2.Label contains 'Realization' or <br /> r2.Label contains 'Composition' or r2.Label contains 'Assignment') and <br /> (not m in cluster and n in cluster) <br /> WITH a , cluster, internal , collect (r2) as external <br /> WHERE size (internal)< size(external) and size(internal) < $internalRels <br /> MATCH p=(a)--(b) <br /> RETURN p

Aliases

The Knot, Artificial Coupling

Tags

microservices, soa, business, application, technology, cohesion, The Couplers, The Change Preventers, between elements, automatic detection

Query parameters

[
    {
        "name": "internalRels",
        "type": "number",
        "default": 3,
        "description": "Number of intenral relationships."
    }
]

Related smells

• Multifaceted Abstraction (relates)
• Dense Structure (relates)
• Hub-like Modularization (relates)

All smells