Entity Relationship Modelling

Is a form of database normalisation based on simple diagrammatical [see page 8, analysis].

The steps are:

[see page 9, Merge] tables that're in a 1:1 relationship (removes the need for a join).
Link tables that're in a 1:M relationship (from M→1).
Introduce a new [see page 10, linker] table to encapsulate each M:N relationship yielding two new 1:M relationships (from M→1). The primary key of the linker table should be a composite key of the intermediate tables.
Find redundant search paths navigating the same sets of rows and [see page 15, delete] the shorter path. That is if you have a foreign key to a table but can reach the same record through a primary key relation into a different table then you have redundancy in your data model.

You can see an example of all this in action [see page 9, here].