14
Operations Planning
and Scheduling
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Stages in Planning and Scheduling
Figure 14.1 – The Relationship of Sales
and Operations Plans and
Schedules to Other Plans
Business or
annual plan
Operations
strategy
Sales and Operations Plan
Forecasting
Sales
Plan
Operations
Plan
Constraint
management
Resource Planning (services)
• Workforce schedule
• Materials and facility resources
Resource Planning (manufacturing)
• Master production schedule
• Material requirements planning
Scheduling
• Employee schedules
• Facility schedules
• Customer schedules
Scheduling
• Employee and equipment schedules
• Production order schedules
• Purchase order schedules
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Sales and Operations Plans
Gather
data
1
Demand
planning
2
Update S&OP
spreadsheets
3
Finalize
and
communicate
6
Executive
S&OP
meeting
5
Consensus
meeting
4
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Gantt Charts
 The job or activity progress chart
 The workstation chart
Current date
Job
4/17 4/18 4/19 4/20 4/21 4/22 4/23 4/24 4/25 4/26
Start activity
Ford
Finish activity
Scheduled
activity time
Nissan
Actual progress
Nonproductive
time
Pontiac
Figure 14.7 – Gantt Progress Chart for an Auto Parts Company
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Gantt Charts
Time
Workstation
Operating
Room A
12
7am 8am 9am 10am 11am pm
Dr. Jon
Adams
1pm 2pm 3pm 4pm 5pm 6pm
Dr. Aubrey Brothers
Operating
Room B
Dr. Gary Case
Operating
Room C
Dr. Jordanne Flowers
Dr. Alaina Bright
Dr. Jeff
Dow
Dr. Madeline Easton
Dr. Dan Gillespie
Figure 14.8 – Gantt Workstation Chart for Operating Rooms at a Hospital
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Scheduling Employees
 Steps in developing a workforce schedule
Step 1: Find all the pairs of consecutive days that
exclude the maximum daily requirements.
Select the unique pair that has the lowest
total requirements for the 2 days
Step 2: If a tie occurs, choose one of the tied
pairs, consistent with the provisions
written into the labor agreement
Step 3: Assign the employees for the selected
pair of days off
Step 4: Repeat steps 1 – 3 until all of the
requirements have been satisfied
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Sequencing Jobs at a Workstation
 Priority sequencing rules

First-come, first-served (FCFS)

Earliest due date (EDD)

Shortest Processing Time (SPT): job requiring
the SPT is the next job to be processed.
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Order
Sequence
determined
by priority
rules
Begin
Work
(1)
Proce
ssing
Time
(Give
n)
(2)
Job
Scheduled
Flow
Customer
time
pickup time
(3) = (1) (given) (4)
+ (2)
Actual
customer
pickup time
(5)
Max = {(3),
(4)}
Hours
early
(6) = (5)
– (3)
Hours
past due
(7) = (5)
– (4)
Average Job Flow time = sum of (3)/ number of orders
Average hours early = sum of (6)/ number of orders
Average hours past due = sum of (7)/ number of orders
Average WIP inventory = sum of (3)/makespan, where makespan (start to complete of all
orders) = job flow time of the last order
Average total inventory = sum of (5)/makespan, where makespan (start to complete of all
orders) = job flow time of the last order
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Schedule jobs for multiple workstations
 Johnson’s rule: A procedure that
minimizes makespan when scheduling a
group of jobs on two workstations.
 Step
1. Find the shortest processing time
among the jobs not yet scheduled. If two or
more jobs are tied, choose one job arbitrarily.
 Step
2. If the shortest processing time is on
workstation 1, schedule the corresponding job
as early as possible. If the shortest processing
time is on workstation 2, schedule the
corresponding job as late as possible.
 Step
3. Eliminate the last job scheduled from
further consideration. Repeat steps 1 and 2
until all jobs have been scheduled.
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