Maybe this will help clear things up.
You're on the right track — in Business Central, Work Type Codes are still the way to define variable costs for a resource based on the type of work (e.g., day shift, night shift, etc.).
Here’s how to do it:
1. Set up Work Type Codes
Go to Work Type Codes page.
Define each type (e.g., DAY, NIGHT) and assign cost and price per unit.
2. Assign Work Type to Resource Usage
When posting job planning lines or job journal lines, select the appropriate Work Type Code.
BC will override the resource's base cost with the cost defined in the Work Type.
3. Use in Jobs
For each job line, the Work Type drives the cost and price used for posting to the job.
> Note: The old “Resource Costs” page is no longer needed — it's now controlled via Work Type Codes and how they are applied during job usage.
So yes, you can manage different labor rates using this feature without changing the base rate of the resource.
Mark below checkbox to make this answer Verified if it helps you. Let me know if you want an example setup.