There are various types of routings used in manufacturing. Manufacturing can use a standard routing, work order routing, alternate routing and a master routing. Let's evaluate each type of routing and what its purpose is.
Standard Routing - This is normally setup from menu 14/G3011 Enter/Change Routing (P3003). This routing is used in Product Costing to roll your associated Standard Costs. This is the suggested machine, labor, setup and queue hours to manufacture an end item. The Standard Routing is created with the routing type 'M'.
Work Order Routing - The Standard Routing is used to create the Work Order Routing (P3112). Calculations are performed using the work order header such as quantity ordered etc. when attaching the Work Order Routing to your Work Order header. This is the routing that is used to produce journal entries along with Capacity Planning (CRP).
Alternate Routing - Users can define different types of routing instructions with different purposes. M is the Standard Manufacturing routing type and any other value different than M is considered an alternate routing type. Alternate routings can be defined in Enter/Change Routing (P3003) field Type of Routing (TRT). Then the routing type to be used on the work order header field is entered and the system then uses the indicated type of routing to attach it to the Work Order routing (F3112).
Master Routing - When there is a need to produce manufactured items that require the exact same process (work centers, setup hours, machine and/or labor), a master routing helps to reduce the number of routings that need to be maintained. Master routings are not branch plant specific like Standard Routings are. This means that you can have multiple items from the same branch plant use the same master routing.
For additional information on any of the above Routings in Manufacturing (Doc ID 627276.1), is a good document to review.