Graphs & PLM ?

Impact Analysis

Allowing impact analysis accross different products, BOMs and multiple production and engineering sites.

http://neo4j.com/use-cases/

Permissions & Access rights

Allowing a more manageable granularity for permissions and access rights, with a fast execution by the software for a better user experience.

http://neo4j.com/use-cases/

Multi-BOM

Context 

Helps working on multi-BOM situations with a better visibility on data manipulated like in Manufacturing BOMs that are trendy.

Cypher

Query language for graphs

Comparison

Cypher / SQL

Navigate the database

MATCH (a:Part) RETURN a

Impact analysis

START a=node() MATCH a-[r]-b RETURN a,r,b

Access Management

MATCH (a:PLMUser),(b:PLMIdentity),(c:Permission) RETURN a,b,c

MATCH (a:PLMUser)-[:isPartOf*]->(b:PLMIdentity)-[:canRead]->(c:Permission)-[:definesAccessTo]->(d:Part) WHERE d.partNumber="X999" RETURN a

For more info :

• contact me
• wikipedia (always a good start)
• Read the Graph databases book 
• Download neo4j and learn Cypher (or OrientDB or any other GraphDB solution from the wikipedia list of 38 projects)