A linear sequence of operations that is an alternative to a sequence of operations in the standard sequence.
You use an alternative sequence for example, if
The production flow is different for certain lot-size ranges
For instance you can machine a work piece on conventional machine or on NC machines. A NC machine has a longer set-up time than a conventional machine. However the machining costs are considerably less. Therefore whether you use NC machines will depend on the lot size.
The production flow changes under certain business conditions.
For instance, if you have a capacity problem, you have some production steps performed externally by a vendor.
You can only create alternative sequences in routings. You cannot create them in reference operation sets, reference rate routings or rate routings.