ERD for a web development company
You're oversimplifying the relations.  No two relations in your diagram are the same, since they don't relate the same domains.  &lt;ORDER&gt; has &lt;ORDER-ITEM&gt; is not the same as &lt;PROJECT&gt; has &lt;PROJECT-PHASE&gt;.  They might both be injective, but that's not sufficient to call them the same.

Try to give your relations more descriptive names.  While attributes (aka one-to-one binary relations) tend to be aggregated on a common determinant to create "entity tables", multivalued attributes and more complicated relations like the ternary relation between Customer, Service and Order-item usually become tables on their own.  Makes really doesn't describe the relation or resulting table properly.

I suggest you add cardinality indicators to your diagram and give your relations more descriptive names, using the predicate statement of each relation for guidance.

On second thought, those names are probably fine in a conceptual design as long as you read them together with the entity sets they relate.  When you get to physical design, 1-to-1 and 1-to-many relations will probably be implemented as attributes of one of the entity sets, so the relation names won't affect the physical design.  The many-to-many relations and non-binary relations will become their own tables, for table names at worst you can concatenate the entity names, e.g. CustomerServiceOrderItems.