Rockwell Automation FactoryTalk Scheduler Users Guide - Manual (Page 29)

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4
Scheduling Features
FactoryTalk Scheduler provides a wide range of features for modeling constrained
scheduling systems. There are four basic categories of modeling constraints available—
resource, sequencing, material, fixture, and operation. We will discuss the major
features for each of them and use the BizBikes tutorial from Chapter 3 to demonstrate
examples.
Resource constraints
FactoryTalk Scheduler provides full support for the scheduling of constrained resources
with four distinct resource types:
„
Singular
„
Infinite
„
Simultaneous
„
Adjustable Pooled
The resource types differ in the functionality that they provide in modeling a wide variety
of production environments.
The Singular resource is the most commonly used type. It represents a single machine,
person, device, jig, fixture, or any resource that is constrained and has a capacity of one.
Tutorial : For our tutorial system, we will model the resources as Singular in work cells
Bend, Cut, Finish, Machine, Weld, Subassembly, and Assembly and Pack, as each
resource can only perform one operation at a time.
The Infinite resource type provides the ability to represent resources that have an
unlimited capacity. The most common example is a subcontractor or a drying area.
Although a subcontractor has a theoretical infinite capacity, it still requires time to
complete the task and may work only a single shift.
Tutorial : We will not use this resource type in our tutorial system.
The Simultaneous resource type represents resources that may have the ability to handle
multiple activities. It is further restricted in that if a Simultaneous resource processes
multiple activities at the same time, all the activities must be synchronized. This means
that they must all start and end at the same time. The significance of this feature is best
described by considering a kiln with a capacity measured in cubic feet. The kiln can be
used to process any number of parts, as long as the volume of the parts does not exceed
the kiln capacity. The synchronized restriction means that once you load and start the kiln,
you must finish that process before it can be used to process any additional parts. You can