Rockwell Automation FactoryTalk Scheduler Users Guide - Manual (Page 42)

F ACTORY T ALK S CHEDULER U SER ’ S G UIDE
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attempt to allow the scheduling of the initial item. If there are insufficient material-
replenish orders to allow the final item to be scheduled, FactoryTalk Scheduler will not
schedule the final item and will remove all items scheduled in the attempt to produce the
material requirements.
Tutorial : In our tutorial, the following items will be modeled as materials, which are
replenished as purchased items and consumed by the production of other products: Pedal
and Chain Assembly, Wheels, Derailleur Assembly, Seat, and Brakes. The materials
Frame, Handlebar, Neck Post, and Seat Post will be replenished by production orders and
consumed by subassembly orders. The materials Finished Frame, Handlebar Assembly,
and Seat Assembly will be replenished by production orders and will consume other
materials. The Final Assembly and Pack order will consume many of the previously
mentioned subassembly and purchased materials.
Fixture constraints
Fixture constraints can be used to model fixtures, tooling, molds, or special material-
handling devices that can be required for more than one successive operation. For ease of
definition, we’ll classify all of these types of devices as “fixtures.” Fixtures differ from
materials in that they are not consumed or produced, although you can vary the number of
available fixtures over time.
A fixture(s) can be required at any operation and held across several following operations
in the same process plan. One operation seizes a number of fixture units and a following
operation releases the units. It’s important to note that the fixture must be released in the
same process plan in which it is seized. It is also possible to seize a fixture at the start of
an operation and release it at the end of the same operation.
Tutorial : This concept is not illustrated in our tutorial.
Operation constraints
In addition to resource, sequencing, and material constraints, there are a number of
operation constraints that can be included in a FactoryTalk Scheduler configuration. We
won’t attempt to cover all these special features in this chapter; we’ll only highlight a few
of the most commonly used features.
FactoryTalk Scheduler provides several features that can alter the way resource setups
constrain the schedule. Most frequently used is the sequence-dependent setup feature that
allows the setup time used for the current operation to be dependent on both the current
and last operation. FactoryTalk Scheduler provides the ability to reference a setup matrix
that includes these times when it is scheduling the operation.
Tutorial : We use this feature in our tutorial to represent the setup times at the Machine
and Bend work cells.