How easy this is to implement can vary quite a bit depending on how the workspace is structured. Just know that bookmarks are visual elements that have no bearing on the order of execution by themselves.

Have a look at the documentation for different strategies on how to control transformer flow:

https://docs.safe.com/fme/html/FME_Desktop_Documentation/FME_Workbench/Workbench/Controlling-Transformer-Flow-at-Runtime.htm

You can also use the FeatureHolder to detain features between transformers (within the same bookmark or between bookmarks).

I'm still pretty new to this. So i've attached a screenshot of the first two bookmarks.

The first is to delete all records (this is running but for some reason not deleteing anything)

The 2nd inserts data from 3 tables into an existing table.

How do I make sure the rows are deleted before FeatureMerger is triggered?

Thanks for the advice so far @geomancer​  @david_r​ 

There is no need to delete all records from a table before adding new features. In the Database Writer you can set Table Handling to 'Truncate Existing' (or 'Drop and Create').

This also makes sure that records will only be removed when FME is about to insert new records.

Use a FeatureWriter, not a classic Writer, then you have a summary output port which you can use to initiate the next step. For example a FeatureReader.

Thanks, this gets rid of my need for the first step!