Work Center Capacity settings are required for all Work Centers
Work Center capacity settings are required to help translate your cycle time raw hours into a more understandable Job Days value that more closely approximates your shop days of operation. Work center capacity settings are used to make the following calculations:
Total Hours/Day
•Work Center Load Days
•Work Center Queue Days
Job Hours/Day
•Job Days Inquiry
•Job Priority
•Slack to Required
•Slack to Finish
•Remaining Job Days Inquiry
Buffer Days
•Job Days Inquiry
For these calculations to have meaningful value, it is important that you establish your work center capacity settings properly according to the guidelines in this chapter.
Settings are maintained in the Work Center Schedule
The following capacity settings are maintained on the Schedule tab within the Work Center Schedule screen.
Total Hours / Day
This setting represents the typical total hours available at a work center in a day. This will be the standard shift hours multiplied by the typical number of machines or workers utilized per shift.
Calculation Formula
The Total Hours / Day setting is calculated as follows:
Shift 1 Hours * Typical # Resources
+ Shift 2 Hours * Typical # Resources
+ Shift 3 Hours * Typical # Resources
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= Total Hours / Day
Shift Hours
The Shift Hours used in the above formula refer to the work center’s standard number of shift hours. Do not include overtime hours unless those hours are always applied as a standard practice.
Typical # Resources (Machines or Workers)
The # Resources in the above formula can be any of the following, depending on the nature of the work center:
Machine-based work centers
Most machine-based work centers consist of one machine, but some work centers have multiple, interchangeable machines. When that is the case, designate the number of machines that can are deployed within each particular shift.
Partially attended machines
Some machines are attended by a worker for only a portion of the time and the worker can potentially oversee multiple work center machines at once. For scheduling purposes, this machine is a single resource for the full available time per shift. From a costing standpoint, these routing sequences should be set to Standard hours type and you can adjust the Work Center Labor Factor to cost the labor at the percentage attended.
Fixed team on a machine
Some machines require a fixed number of workers to operate. For scheduling purposes, this machine is a single resource for the full available time per shift. From a costing standpoint, these routing sequences should be set to Standard hours type and you can adjust the Work Center Labor Factor to multiply by the number of members of the fixed team.
Worker-based work centers
Designate the typical number of workers that are deployed for each shift. If the work center has very flexible capacity where you can flex workers in and out as needed, do your best to choose a typical number of workers per shift utilized.
Example
If you had two 8 hour shifts with a typical deployment of three workers on Shift 1 and one worker on Shift 2, here is a sample calculation:
Shift 1 = 8 hours x 3 workers = 24 Hours
Shift 2 = 8 hours x 1 worker = 8 Hours
Total Hours / Day = 32 Hours
How often should this setting be changed?
In order for capacity metric to have comparison value over time, if is important that all three settings stay fixed and only get updated when capacity significantly changes, such as when you add or subtract a shift, machine, or workstation. These settings represent a potential or typical capacity and are not to be used to reflect actual hours being deployed or the queue days that exist on any given day.
Job Hours / Day
This setting represents the total job hours in a day based on your typical job sequence deployment strategy at this work center. This will be the standard shift hours multiplied by the typical number of machines or workers utilized per Job Sequence. The key question is do you typically assign multiple workers or machines to a single job sequence in production or do you assign one worker/machine per sequence?
Calculation Formula
The Job Hours / Day setting is calculated as follows:
Shift 1 Hours * # Resources per Job Sequence
+ Shift 2 Hours * # Resources per Job Sequence
+ Shift 3 Hours * # Resources per Job Sequence
------------------------------------------------------------------------
= Job Hours / Day
Shift Hours
Use the same Shift Hours as in the Total Hours / Day setting above.
# Resources per Job Sequence
This is the number of resources typically applied per job sequence. For example, a work center may have three machines, but due to tooling limitations a job sequence can only be run on one machine at a time. As another example, a work center may have a capacity of six daily workers, but a job sequence can only be performed by one worker at a time.
Worker-based work center discussion
How you deploy your workers in the Work Center schedule is under your control. If your policy at a work center is to assign multiple workers to a single job sequence until the sequence is completed, then your Total Hours/Day and your Job Hours / Day can be equal. If it is your policy that each worker works on their own sequences independently, then the number of resources per Job Sequence would be set to one for the calculation above. You may also land somewhere in between, where your policy is to assign sequences to two workers at a time. For your Job Days calculations to make sense, it will be helpful if you match your typical deployment per sequence strategy in your Job Hours / Day setting.
Example
If you had one 8 hour shift with 3 workers typically deployed to the work center (Total Hrs / Day = 24). The chart below shows the Job Hrs / Day calculation based on your deployment method at this work center. We have also included a column for the affect on the calculated Job Days for a Job that has 50 Job Hours based on its cycle times. You can see if you dedicate multiple workers to a single sequence you will finish your individual jobs much quicker.
Shift Hours |
# Workers Assigned Job Sequence |
Job Hrs / Day |
Job Days based on 50 Job Hours |
8 |
1 |
8 |
6.25 |
8 |
2 |
16 |
3.13 |
8 |
3 |
24 |
2.08 |
Buffer Days
This setting serves two purposes:
Accounts for queue days in the Job Days Inquiry
In the Job Days Inquiry, which is used to help determine an item’s Job Days setting, the Buffer Days allocates additional time against job sequences to account for typical queue days. During the course of a job, more time is often spent waiting in work center queues than in actual production. Enter what you consider to be a typical queue days for the work center, which can be a decimal amount for work centers with relatively short queue times.
Sets the target queue size for Queue Control
When a work center is subject to Queue Control, the Buffer Days setting also establishes the work center’s target queue size. See the Using Queue Control chapter for details.
