Rockwell Automation FactoryTalk Scheduler Users Guide - Manual (Page 31)

4 • S CHEDULING F EATURES
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called Assembly and Pack Area 1 and Assembly and Pack Area 2. We will associate a 1/5-
shift pattern with all the resources.
The combination of the availability of required resources and resource efficiencies
determine both where and how FactoryTalk Scheduler places an operation on the planning
board during the scheduling process. A resource becomes unavailable for use by an
operation in a given time period if it is currently being used by another operation or if it is
in an off-shift state.
Simultaneous, Singular, and Infinite resource spanning
Consider an operation that requires two hours of processing time on a Singular resource.
Assume that the resource is continuously on-shift starting at 7
AM until 3 PM and is off-
shift the rest of the day. Also assume that there are no other operations currently using the
resource. If the operation were unable to start until 12:30
PM , FactoryTalk Scheduler
would schedule the operation from 12:30 PM to 2:30 PM , taking a continuous two-hour
span of time. However, if the operation were unable to start until 2 PM , FactoryTalk
Scheduler would schedule the operation to start at 2
PM
on the current day, where it would
process for one hour. It would then resume processing the next day at 7 AM to complete
the two-hour operation by 8 AM .
When an operation crosses a time where a resource is in an off-shift state or at a reduced
efficiency, it is called spanning. If an operation requires several secondary resources with
different shift patterns, the spanning can become quite complicated. However, as long as
all the required resources are Simultaneous, Singular, or Infinite types, no other operations
can use these resources during the span time of the scheduled operation. Note that if one
of these resources is a Simultaneous type, other operations may use any excess capacity.
Adjustable Pooled resource spanning
Adjustable Pooled resources differ not only in the manner in which resource spanning is
allowed, but also because you can elect to not allow certain types of spanning for
individual Adjustable Pooled resources. We’ll first discuss the default spanning mode.
The spanning behavior of Adjustable Pooled resources is best illustrated with an example.
The diagram below shows the availability profile of a labor resource. This profile
represents a 2/5 shift pattern with three workers available during the first shift (7
AM to
3 PM ), two available during the second shift (3 PM to 11 PM ), and none available during the
third shift. Note that the diagram shows that there is currently an operation, represented by
the white area, which has been allocated one labor unit from 10
AM to 9 PM on Day 1.