FME Workbench allows you to replace a sequence of existing transformers with a single "custom" transformer. Custom transformers execute the same data flow as the original transformers, and can be edited just like any other transformer. You can use Custom Transformers in two ways:
create them to store and use locally on your computer
export them to edit independently or share with other users
Custom transformers can be used:
to streamline a large workspace
to make various data flows within a workspace more understandable and easier to document
as a replacement for the same chain of transformers multiple times within the same workspace
You can also export a Custom Transformer to share with other users. After they are exported, custom transformers can be:
edited independently of any workspace
shared with other users (via e-mail or shared directories)
embedded or linked in any number of workspaces
stored as a separate .fmx file
The easiest way to create a custom transformer is by opening an existing workspace and selecting existing transformers:
You can also build a new Custom Transformer from a blank canvas:
By default, custom transformers are stored in My Documents\FME\Transformers.