Following are the reasons why we go for DAC
- Scheduling Tasks: It helps in scheduling an execution plan run. An execution plan can be scheduled for different frequencies or recurrences by defining multiple schedules. (An execution plan is defined based on business requirements for when the data warehouse needs to be loaded. Execution plans are scheduled in sequence, not in parallel)
- Automate Execution: It can be quite difficult and error prone to run different workflows manually and DAC helps us to automate execution of workflows according to our needs.
- Easy Flow Management: It helps easy management of workflow execution. Take a simple example I have created 5 different workflows 3rd should only be run after 4th and 5th workflow. Running them manually can always leave a possibility of error and result in wrong data load. DAC can help us define dependency and order of the workflows in which they should be run.
Also DAC manage the performance by dropping indexes, truncating stage tables, rebuilding the indexes, and analyzing the tables during the process
If you do not use DAC, you have to write your own custom change capture process and need to redesign from scratch an ETL method that allow the restart of the ETL process from point of failure at record level. The biggest saving is that DAC can survive during the upgrade , while your custom processes cannot.