Planner Workbench vs Prodution Planning Workbench vs Job Status Maintenance vs Job Manager

Each has its own purpose:

Job Manager: allows you to look at a PART, and see all the Inventory, and Inventory Demands, and Supplies, and to manipulate the related jobs. You can create new jobs, split jobs, unlink jobs, join jobs, etc. 

Job Status Maintenance: This allows you to search out a list of jobs (by planner or part) and maintain their status… firming, engineering releasing, printing, etc. it is designed to help with the job release process for a planner.

Planning Workbench: This is a special place where you can find suggested demands to create jobs for any manufactured items. For example, if you have a part that has nothing on hand, and you create a sales order for that item, it will immediately show up here because there is not a job yet. You can create jobs from here to meet those demands. If you have MRP, and you run MRP, then any demands that show on this workbench will disappear UNLESS there is not a valid BOM for the part.

Production Planner Workbench: This is probably a little mis-named so it can be confusing… Also, before running this workbench, you need to run the Production Planning Process which generates the data used by the workbench. Once generated, you go into the workbench, and it allows you to see Inventory with Shortages, jobs with shortages, Inventory with no shortages, jobs with no shortages, etc. It can be a little confusing at first, but once you get a handle on how it works, it has a ton of detail.