SchedulinSchedulingg

Manufacturing ProcessManufacturing Process

Manufacturing ProcessManufacturing Process

Sh

ipp

ing

Dep

art

men

t

Raw

Ma

teri

als

Legend:

Batch of parts

Workstation

Manufacturing ProcessManufacturing Process

Sh

ipp

ing

Dep

art

men

t

Raw

Ma

teri

als

Legend:

Batch of parts

Workstation

Manufacturing ProcessManufacturing Process

Sh

ipp

ing

Dep

art

men

t

Raw

Ma

teri

als

Legend:

Batch of parts

Workstation

Manufacturing ProcessManufacturing Process

Sh

ipp

ing

Dep

art

men

t

Raw

Ma

teri

als

Legend:

Batch of parts

Workstation

Manufacturing ProcessManufacturing Process

Sh

ipp

ing

Dep

art

men

t

Raw

Ma

teri

als

Legend:

Batch of parts

Workstation

Manufacturing ProcessManufacturing Process

Sh

ipp

ing

Dep

art

men

t

Raw

Ma

teri

als

Legend:

Batch of parts

Workstation

Manufacturing ProcessManufacturing Process

Sh

ipp

ing

Dep

art

men

t

Raw

Ma

teri

als

Legend:

Batch of parts

Workstation

Gantt ChartsGantt Charts

Gantt ChartsGantt ChartsProgress Chart

Plymouth

Ford

Pontiac

Job 4/20 4/22 4/23 4/24 4/25 4/264/214/17 4/18 4/19

Figure 17.2

Gantt ChartsGantt ChartsProgress Chart

Plymouth

Ford

Pontiac

Job 4/20 4/22 4/23 4/24 4/25 4/264/214/17 4/18 4/19

Figure 17.2

Gantt ChartsGantt ChartsProgress Chart

Plymouth

Ford

Pontiac

Job 4/20 4/22 4/23 4/24 4/25 4/264/214/17 4/18 4/19

Figure 17.2

Gantt ChartsGantt ChartsProgress Chart

Plymouth

Ford

Pontiac

Job 4/20 4/22 4/23 4/24 4/25 4/264/214/17 4/18 4/19

Current date

Figure 17.2

Gantt ChartsGantt ChartsMachine Chart

Machine 4/20 4/22 4/23 4/24 4/25 4/264/21

Grinder

Lathe

Figure 17.3

Gantt ChartsGantt ChartsMachine Chart

Machine 4/20 4/22 4/23 4/24 4/25 4/26

Plymouth Pontiac Ford

PlymouthPontiac Ford

4/21

Grinder

Lathe

Figure 17.3

Gantt ChartsGantt ChartsMachine Chart

Machine 4/20 4/22 4/23 4/24 4/25 4/26

Plymouth Pontiac Ford

PlymouthPontiac Ford

4/21

Grinder

Lathe

Figure 17.3

Current date

Machine 4/20 4/22 4/23 4/24 4/25 4/26

Grinder

Lathe

Plymouth Pontiac Ford

PlymouthPontiac Ford

4/21

Gantt ChartsGantt ChartsMachine ChartFigure 17.3

Performance MeasuresPerformance Measures

Job flow time= Time of completion

- Time job was available for first processing

Makespan= Time of completion of last job - Starting time of first job

Past due Work-in-process inventory Total inventory

= Scheduled receipts for all items + On-hand inventories of all items

Utilization= Productive work time/Total work time available

Dispatching Procedures - StaticDispatching Procedures - Static

Earliest due date (EDD) First come, first served (FCFS) Last come, first served (LCFS) Shortest processing time (SPT)

Critical ratio ( CR )

(Due date - Today’s date) / Total shop time remaining

• Slack time remaining (STR)

Time to due date - Total shop time remaining

• Slack per remaining operations (STR/OP)STR / Number of operations remaining

Dispatching Procedures - DynamicDispatching Procedures - Dynamic

SequencingSequencingSingle-Dimension Rules

SequencingSequencingSingle-Dimension Rules - EDD

Job Scheduled ActualEngine Processing Flow Customer Customer HoursBlock Begin Time Time Pickup Pickup Hours Past

Sequence Work (hr) (hr) Time Time Early Due

Ranger 8 10Explorer 6 12Econoline 150 3 18Bronco 15 20Thunderbird 12 22

Example 17.1

SequencingSequencingSingle-Dimension Rules - EDD

Job Scheduled ActualEngine Processing Flow Customer Customer HoursBlock Begin Time Time Pickup Pickup Hours Past

Sequence Work (hr) (hr) Time Time Early Due

Ranger 0 + 8 = 8 10Explorer 6 12Econoline 150 3 18Bronco 15 20Thunderbird 12 22

Example 17.1

SequencingSequencingSingle-Dimension Rules - EDD

Job Scheduled ActualEngine Processing Flow Customer Customer HoursBlock Begin Time Time Pickup Pickup Hours Past

Sequence Work (hr) (hr) Time Time Early Due

Ranger 0 + 8 = 8 10 10 2Explorer 6 12Econoline 150 3 18Bronco 15 20Thunderbird 12 22

Example 17.1

SequencingSequencingSingle-Dimension Rules - EDD

Job Scheduled ActualEngine Processing Flow Customer Customer HoursBlock Begin Time Time Pickup Pickup Hours Past

Sequence Work (hr) (hr) Time Time Early Due

Ranger 0 + 8 = 8 10 10 2Explorer 8 + 6 = 14 12 14 2Econoline 150 3 18Bronco 15 20Thunderbird 12 22

Example 17.1

SequencingSequencingSingle-Dimension Rules - EDD

Job Scheduled ActualEngine Processing Flow Customer Customer HoursBlock Begin Time Time Pickup Pickup Hours Past

Sequence Work (hr) (hr) Time Time Early Due

Ranger 0 + 8 = 8 10 10 2Explorer 8 + 6 = 14 12 14 2Econoline 150 14 + 3 = 17 18 18 1Bronco 15 20Thunderbird 12 22

Example 17.1

SequencingSequencingSingle-Dimension Rules - EDD

Job Scheduled ActualEngine Processing Flow Customer Customer HoursBlock Begin Time Time Pickup Pickup Hours Past

Sequence Work (hr) (hr) Time Time Early Due

Ranger 0 + 8 = 8 10 10 2Explorer 8 + 6 = 14 12 14 2Econoline 150 14 + 3 = 17 18 18 1Bronco 17 + 15 = 32 20 32 12Thunderbird 12 22

Example 17.1

SequencingSequencingSingle-Dimension Rules - EDD

Job Scheduled ActualEngine Processing Flow Customer Customer HoursBlock Begin Time Time Pickup Pickup Hours Past

Sequence Work (hr) (hr) Time Time Early Due

Ranger 0 + 8 = 8 10 10 2Explorer 8 + 6 = 14 12 14 2Econoline 150 14 + 3 = 17 18 18 1Bronco 17 + 15 = 32 20 32 12Thunderbird 32 + 12 = 44 22 44 22

Example 17.1

SequencingSequencingSingle-Dimension Rules - EDD

Job Scheduled ActualEngine Processing Flow Customer Customer HoursBlock Begin Time Time Pickup Pickup Hours Past

Sequence Work (hr) (hr) Time Time Early Due

Ranger 0 + 8 = 8 10 10 2Explorer 8 + 6 = 14 12 14 2Econoline 150 14 + 3 = 17 18 18 1Bronco 17 + 15 = 32 20 32 12Thunderbird 32 + 12 = 44 22 44 22

Average job flow time =8 + 14 + 17 + 32 + 44

5

Example 17.1

SequencingSequencingSingle-Dimension Rules - EDD

Job Scheduled ActualEngine Processing Flow Customer Customer HoursBlock Begin Time Time Pickup Pickup Hours Past

Sequence Work (hr) (hr) Time Time Early Due

Ranger 0 + 8 = 8 10 10 2Explorer 8 + 6 = 14 12 14 2Econoline 150 14 + 3 = 17 18 18 1Bronco 17 + 15 = 32 20 32 12Thunderbird 32 + 12 = 44 22 44 22

Average job flow time = 23 hours

Example 17.1

SequencingSequencingSingle-Dimension Rules - EDD

Job Scheduled ActualEngine Processing Flow Customer Customer HoursBlock Begin Time Time Pickup Pickup Hours Past

Sequence Work (hr) (hr) Time Time Early Due

Ranger 0 + 8 = 8 10 10 2Explorer 8 + 6 = 14 12 14 2Econoline 150 14 + 3 = 17 18 18 1Bronco 17 + 15 = 32 20 32 12Thunderbird 32 + 12 = 44 22 44 22

Average job flow time = 23 hours Average hours early =

2 + 0 + 1 + 0 + 05

Example 17.1

SequencingSequencingSingle-Dimension Rules - EDD

Job Scheduled ActualEngine Processing Flow Customer Customer HoursBlock Begin Time Time Pickup Pickup Hours Past

Sequence Work (hr) (hr) Time Time Early Due

Ranger 0 + 8 = 8 10 10 2Explorer 8 + 6 = 14 12 14 2Econoline 150 14 + 3 = 17 18 18 1Bronco 17 + 15 = 32 20 32 12Thunderbird 32 + 12 = 44 22 44 22

Average job flow time = 23 hours Average hours early = 0.6 hour

Example 17.1

SequencingSequencingSingle-Dimension Rules - EDD

Job Scheduled ActualEngine Processing Flow Customer Customer HoursBlock Begin Time Time Pickup Pickup Hours Past

Sequence Work (hr) (hr) Time Time Early Due

Ranger 0 + 8 = 8 10 10 2Explorer 8 + 6 = 14 12 14 2Econoline 150 14 + 3 = 17 18 18 1Bronco 17 + 15 = 32 20 32 12Thunderbird 32 + 12 = 44 22 44 22

Average job flow time = 23 hours Average hours early = 0.6 hour

Average hours past due = 0 + 2 + 0 + 12 + 22

5

Example 17.1

SequencingSequencingSingle-Dimension Rules - EDD

Job Scheduled ActualEngine Processing Flow Customer Customer HoursBlock Begin Time Time Pickup Pickup Hours Past

Sequence Work (hr) (hr) Time Time Early Due

Ranger 0 + 8 = 8 10 10 2Explorer 8 + 6 = 14 12 14 2Econoline 150 14 + 3 = 17 18 18 1Bronco 17 + 15 = 32 20 32 12Thunderbird 32 + 12 = 44 22 44 22

Average job flow time = 23 hours Average hours early = 0.6 hour

Average hours past due = 7.2 hours

Example 17.1

SequencingSequencingSingle-Dimension Rules - EDD

Job Scheduled ActualEngine Processing Flow Customer Customer HoursBlock Begin Time Time Pickup Pickup Hours Past

Sequence Work (hr) (hr) Time Time Early Due

Ranger 0 + 8 = 8 10 10 2Explorer 8 + 6 = 14 12 14 2Econoline 150 14 + 3 = 17 18 18 1Bronco 17 + 15 = 32 20 32 12Thunderbird 32 + 12 = 44 22 44 22

Average job flow time = 23 hours Average hours early = 0.6 hour

Average hours past due = 7.2 hours Average WIP = Sum of flow times

Makespan

Example 17.1

SequencingSequencingSingle-Dimension Rules - EDD

Job Scheduled ActualEngine Processing Flow Customer Customer HoursBlock Begin Time Time Pickup Pickup Hours Past

Sequence Work (hr) (hr) Time Time Early Due

Ranger 0 + 8 = 8 10 10 2Explorer 8 + 6 = 14 12 14 2Econoline 150 14 + 3 = 17 18 18 1Bronco 17 + 15 = 32 20 32 12Thunderbird 32 + 12 = 44 22 44 22

Average job flow time = 23 hours Average hours early = 0.6 hour

Average hours past due = 7.2 hours Average WIP = 8 + 14 + 17 + 32 + 44

44

Example 17.1

SequencingSequencingSingle-Dimension Rules - EDD

Job Scheduled ActualEngine Processing Flow Customer Customer HoursBlock Begin Time Time Pickup Pickup Hours Past

Sequence Work (hr) (hr) Time Time Early Due

Ranger 0 + 8 = 8 10 10 2Explorer 8 + 6 = 14 12 14 2Econoline 150 14 + 3 = 17 18 18 1Bronco 17 + 15 = 32 20 32 12Thunderbird 32 + 12 = 44 22 44 22

Average job flow time = 23 hours Average hours early = 0.6 hour

Average hours past due = 7.2 hours Average WIP = 2.61 blocks

Example 17.1

SequencingSequencingSingle-Dimension Rules - EDD

Job Scheduled ActualEngine Processing Flow Customer Customer HoursBlock Begin Time Time Pickup Pickup Hours Past

Sequence Work (hr) (hr) Time Time Early Due

Ranger 0 + 8 = 8 10 10 2Explorer 8 + 6 = 14 12 14 2Econoline 150 14 + 3 = 17 18 18 1Bronco 17 + 15 = 32 20 32 12Thunderbird 32 + 12 = 44 22 44 22

Average job flow time = 23 hours Average hours early = 0.6 hour

Average hours past due = 7.2 hours Average WIP = 2.61 blocks

Average total inventory =Sum of time in system

Makespan

Example 17.1

SequencingSequencingSingle-Dimension Rules - EDD

Job Scheduled ActualEngine Processing Flow Customer Customer HoursBlock Begin Time Time Pickup Pickup Hours Past

Sequence Work (hr) (hr) Time Time Early Due

Ranger 0 + 8 = 8 10 10 2Explorer 8 + 6 = 14 12 14 2Econoline 150 14 + 3 = 17 18 18 1Bronco 17 + 15 = 32 20 32 12Thunderbird 32 + 12 = 44 22 44 22

Average job flow time = 23 hours Average hours early = 0.6 hour

Average hours past due = 7.2 hours Average WIP = 2.61 blocks

Average total inventory =10 + 14 + 18 + 32 + 44

44

Example 17.1

SequencingSequencingSingle-Dimension Rules - EDD

Job Scheduled ActualEngine Processing Flow Customer Customer HoursBlock Begin Time Time Pickup Pickup Hours Past

Sequence Work (hr) (hr) Time Time Early Due

Ranger 0 + 8 = 8 10 10 2Explorer 8 + 6 = 14 12 14 2Econoline 150 14 + 3 = 17 18 18 1Bronco 17 + 15 = 32 20 32 12Thunderbird 32 + 12 = 44 22 44 22

Average job flow time = 23 hours Average hours early = 0.6 hour

Average hours past due = 7.2 hours Average WIP = 2.61 blocks

Average total inventory = 2.68 engine blocks

Example 17.1

SequencingSequencingSingle-Dimension Rules - SPT

Example 17.1

SequencingSequencingSingle-Dimension Rules - SPT

Job Scheduled ActualEngine Processing Flow Customer Customer HoursBlock Begin Time Time Pickup Pickup Hours Past

Sequence Work (hr) (hr) Time Time Early Due

Econoline 150 0 + 3 = 3 18 18 15Explorer 3 + 6 = 9 12 12 3Ranger 6 + 8 = 17 10 17 7Thunderbird 17 + 12 = 29 22 29 7Bronco 29 + 15 = 44 20 44 24

Average job flow time = 20.4 hours Average hours early = 3.6 hour

Average hours past due = 7.6 hours Average WIP = 2.32 blocks

Average total inventory = 2.73 engine blocks

Example 17.1

SequencingSequencingSingle-Dimension Rules - SPT

Job Scheduled ActualEngine Processing Flow Customer Customer HoursBlock Begin Time Time Pickup Pickup Hours Past

Sequence Work (hr) (hr) Time Time Early Due

Econoline 150 0 + 3 = 3 18 18 15Explorer 3 + 6 = 9 12 12 3Ranger 6 + 8 = 17 10 17 7Thunderbird 17 + 12 = 29 22 29 7Bronco 29 + 15 = 44 20 44 24

Average job flow time = 20.4 hours Average hours early = 3.6 hour

Average hours past due = 7.6 hours Average WIP = 2.32 blocks

Average total inventory = 2.73 engine blocks

Rule Comparison

EDD SPT

Average job flow time 23 20.4Average hours early 0.6 3.6Average hours past due 7.2 7.6Average WIP 2.61 2.32Average total inventory 2.68 2.73

Example 17.1

SequencingSequencingMultiple-Dimension Rules

SequencingSequencingMultiple-Dimension Rules

1 2.3 15 10 6.12 10.5 10 2 7.83 6.2 20 12 14.54 15.6 8 5 10.2

Operation TimeTime at Remaining Number ofEngine to Due Date Operations Shop Time

Job Lathe (hr) (Days) Remaining Remaining CR S/RO

Example 17.2

SequencingSequencingMultiple-Dimension Rules

1 2.3 15 10 6.12 10.5 10 2 7.83 6.2 20 12 14.54 15.6 8 5 10.2

Operation TimeTime at Remaining Number ofEngine to Due Date Operations Shop Time

Job Lathe (hr) (Days) Remaining Remaining CR S/RO

CR = Time remaining to due date

Shop time remaining

Example 17.2

SequencingSequencingMultiple-Dimension Rules

1 2.3 15 10 6.12 10.5 10 2 7.83 6.2 20 12 14.54 15.6 8 5 10.2

Operation TimeTime at Remaining Number ofEngine to Due Date Operations Shop Time

Job Lathe (hr) (Days) Remaining Remaining CR S/RO

CR = 156.1

Example 17.2

SequencingSequencingMultiple-Dimension Rules

1 2.3 15 10 6.12 10.5 10 2 7.83 6.2 20 12 14.54 15.6 8 5 10.2

Operation TimeTime at Remaining Number ofEngine to Due Date Operations Shop Time

Job Lathe (hr) (Days) Remaining Remaining CR S/RO

CR = = 2.46156.1

Example 17.2

SequencingSequencingMultiple-Dimension Rules

1 2.3 15 10 6.1 2.462 10.5 10 2 7.83 6.2 20 12 14.54 15.6 8 5 10.2

Operation TimeTime at Remaining Number ofEngine to Due Date Operations Shop Time

Job Lathe (hr) (Days) Remaining Remaining CR S/RO

CR = = 2.46156.1

Example 17.2

SequencingSequencingMultiple-Dimension Rules

1 2.3 15 10 6.1 2.462 10.5 10 2 7.8 1.283 6.2 20 12 14.5 1.384 15.6 8 5 10.2 0.78

Operation TimeTime at Remaining Number ofEngine to Due Date Operations Shop Time

Job Lathe (hr) (Days) Remaining Remaining CR S/RO

Example 17.2

SequencingSequencingMultiple-Dimension Rules

1 2.3 15 10 6.1 2.462 10.5 10 2 7.8 1.283 6.2 20 12 14.5 1.384 15.6 8 5 10.2 0.78

Operation TimeTime at Remaining Number ofEngine to Due Date Operations Shop Time

Job Lathe (hr) (Days) Remaining Remaining CR S/RO

S/RO = Time remaining to due date - Shop time remaining

Number of operations remaining

Example 17.2

SequencingSequencingMultiple-Dimension Rules

1 2.3 15 10 6.1 2.462 10.5 10 2 7.8 1.283 6.2 20 12 14.5 1.384 15.6 8 5 10.2 0.78

Operation TimeTime at Remaining Number ofEngine to Due Date Operations Shop Time

Job Lathe (hr) (Days) Remaining Remaining CR S/RO

S/RO = 15 - 6.1

10Example 17.2

SequencingSequencingMultiple-Dimension Rules

1 2.3 15 10 6.1 2.462 10.5 10 2 7.8 1.283 6.2 20 12 14.5 1.384 15.6 8 5 10.2 0.78

Operation TimeTime at Remaining Number ofEngine to Due Date Operations Shop Time

Job Lathe (hr) (Days) Remaining Remaining CR S/RO

S/RO = = 0.8915 - 6.1

10Example 17.2

SequencingSequencingMultiple-Dimension Rules

1 2.3 15 10 6.1 2.46 0.892 10.5 10 2 7.8 1.283 6.2 20 12 14.5 1.384 15.6 8 5 10.2 0.78

Operation TimeTime at Remaining Number ofEngine to Due Date Operations Shop Time

Job Lathe (hr) (Days) Remaining Remaining CR S/RO

S/RO = = 0.8915 - 6.1

10Example 17.2

SequencingSequencingMultiple-Dimension Rules

1 2.3 15 10 6.1 2.46 0.892 10.5 10 2 7.8 1.28 1.103 6.2 20 12 14.5 1.38 0.464 15.6 8 5 10.2 0.78 - 0.44

Operation TimeTime at Remaining Number ofEngine to Due Date Operations Shop Time

Job Lathe (hr) (Days) Remaining Remaining CR S/RO

Example 17.2

SequencingSequencingMultiple-Dimension Rules

1 2.3 15 10 6.1 2.46 0.892 10.5 10 2 7.8 1.28 1.103 6.2 20 12 14.5 1.38 0.464 15.6 8 5 10.2 0.78 - 0.44

Operation TimeTime at Remaining Number ofEngine to Due Date Operations Shop Time

Job Lathe (hr) (Days) Remaining Remaining CR S/RO

CR Sequence =

Example 17.2

SequencingSequencingMultiple-Dimension Rules

1 2.3 15 10 6.1 2.46 0.892 10.5 10 2 7.8 1.28 1.103 6.2 20 12 14.5 1.38 0.464 15.6 8 5 10.2 0.78 - 0.44

Operation TimeTime at Remaining Number ofEngine to Due Date Operations Shop Time

Job Lathe (hr) (Days) Remaining Remaining CR S/RO

CR Sequence = 4

Example 17.2

SequencingSequencingMultiple-Dimension Rules

1 2.3 15 10 6.1 2.46 0.892 10.5 10 2 7.8 1.28 1.103 6.2 20 12 14.5 1.38 0.464 15.6 8 5 10.2 0.78 - 0.44

Operation TimeTime at Remaining Number ofEngine to Due Date Operations Shop Time

Job Lathe (hr) (Days) Remaining Remaining CR S/RO

CR Sequence = 4 - 2

Example 17.2

SequencingSequencingMultiple-Dimension Rules

1 2.3 15 10 6.1 2.46 0.892 10.5 10 2 7.8 1.28 1.103 6.2 20 12 14.5 1.38 0.464 15.6 8 5 10.2 0.78 - 0.44

Operation TimeTime at Remaining Number ofEngine to Due Date Operations Shop Time

Job Lathe (hr) (Days) Remaining Remaining CR S/RO

CR Sequence = 4 - 2 - 3

Example 17.2

SequencingSequencingMultiple-Dimension Rules

1 2.3 15 10 6.1 2.46 0.892 10.5 10 2 7.8 1.28 1.103 6.2 20 12 14.5 1.38 0.464 15.6 8 5 10.2 0.78 - 0.44

Operation TimeTime at Remaining Number ofEngine to Due Date Operations Shop Time

Job Lathe (hr) (Days) Remaining Remaining CR S/RO

CR Sequence = 4 - 2 - 3 - 1

Example 17.2

SequencingSequencingMultiple-Dimension Rules

1 2.3 15 10 6.1 2.46 0.892 10.5 10 2 7.8 1.28 1.103 6.2 20 12 14.5 1.38 0.464 15.6 8 5 10.2 0.78 - 0.44

Operation TimeTime at Remaining Number ofEngine to Due Date Operations Shop Time

Job Lathe (hr) (Days) Remaining Remaining CR S/RO

CR Sequence = 4 - 2 - 3 - 1S/RO Sequence =

Example 17.2

SequencingSequencingMultiple-Dimension Rules

1 2.3 15 10 6.1 2.46 0.892 10.5 10 2 7.8 1.28 1.103 6.2 20 12 14.5 1.38 0.464 15.6 8 5 10.2 0.78 - 0.44

Operation TimeTime at Remaining Number ofEngine to Due Date Operations Shop Time

Job Lathe (hr) (Days) Remaining Remaining CR S/RO

CR Sequence = 4 - 2 - 3 - 1S/RO Sequence = 4

Example 17.2

SequencingSequencingMultiple-Dimension Rules

1 2.3 15 10 6.1 2.46 0.892 10.5 10 2 7.8 1.28 1.103 6.2 20 12 14.5 1.38 0.464 15.6 8 5 10.2 0.78 - 0.44

Operation TimeTime at Remaining Number ofEngine to Due Date Operations Shop Time

Job Lathe (hr) (Days) Remaining Remaining CR S/RO

CR Sequence = 4 - 2 - 3 - 1S/RO Sequence = 4 - 3

Example 17.2

SequencingSequencingMultiple-Dimension Rules

1 2.3 15 10 6.1 2.46 0.892 10.5 10 2 7.8 1.28 1.103 6.2 20 12 14.5 1.38 0.464 15.6 8 5 10.2 0.78 - 0.44

Operation TimeTime at Remaining Number ofEngine to Due Date Operations Shop Time

Job Lathe (hr) (Days) Remaining Remaining CR S/RO

CR Sequence = 4 - 2 - 3 - 1S/RO Sequence = 4 - 3 - 1

Example 17.2

SequencingSequencingMultiple-Dimension Rules

1 2.3 15 10 6.1 2.46 0.892 10.5 10 2 7.8 1.28 1.103 6.2 20 12 14.5 1.38 0.464 15.6 8 5 10.2 0.78 - 0.44

Operation TimeTime at Remaining Number ofEngine to Due Date Operations Shop Time

Job Lathe (hr) (Days) Remaining Remaining CR S/RO

CR Sequence = 4 - 2 - 3 - 1S/RO Sequence = 4 - 3 - 1 - 2

Example 17.2

SequencingSequencingMultiple-Dimension Rules

1 2.3 15 10 6.1 2.46 0.892 10.5 10 2 7.8 1.28 1.103 6.2 20 12 14.5 1.38 0.464 15.6 8 5 10.2 0.78 - 0.44

Operation TimeTime at Remaining Number ofEngine to Due Date Operations Shop Time

Job Lathe (hr) (Days) Remaining Remaining CR S/RO

CR Sequence = 4 - 2 - 3 - 1S/RO Sequence = 4 - 3 - 1 - 2

Sequence Summary

Example 17.2

SequencingSequencingMultiple-Dimension Rules

1 2.3 15 10 6.1 2.46 0.892 10.5 10 2 7.8 1.28 1.103 6.2 20 12 14.5 1.38 0.464 15.6 8 5 10.2 0.78 - 0.44

Operation TimeTime at Remaining Number ofEngine to Due Date Operations Shop Time

Job Lathe (hr) (Days) Remaining Remaining CR S/RO

CR Sequence = 4 - 2 - 3 - 1S/RO Sequence = 4 - 3 - 1 - 2

Sequence Summary

FCFS = 1 - 2 - 3 - 4

Example 17.2

SequencingSequencingMultiple-Dimension Rules

1 2.3 15 10 6.1 2.46 0.892 10.5 10 2 7.8 1.28 1.103 6.2 20 12 14.5 1.38 0.464 15.6 8 5 10.2 0.78 - 0.44

Operation TimeTime at Remaining Number ofEngine to Due Date Operations Shop Time

Job Lathe (hr) (Days) Remaining Remaining CR S/RO

CR Sequence = 4 - 2 - 3 - 1S/RO Sequence = 4 - 3 - 1 - 2

Sequence Summary

FCFS = 1 - 2 - 3 - 4SPT = 1 - 3 - 2 - 4

Example 17.2

SequencingSequencingMultiple-Dimension Rules

1 2.3 15 10 6.1 2.46 0.892 10.5 10 2 7.8 1.28 1.103 6.2 20 12 14.5 1.38 0.464 15.6 8 5 10.2 0.78 - 0.44

Operation TimeTime at Remaining Number ofEngine to Due Date Operations Shop Time

Job Lathe (hr) (Days) Remaining Remaining CR S/RO

CR Sequence = 4 - 2 - 3 - 1S/RO Sequence = 4 - 3 - 1 - 2

Sequence Summary

FCFS = 1 - 2 - 3 - 4SPT = 1 - 3 - 2 - 4EDD = 4 - 2 - 1 - 3

Example 17.2

SequencingSequencingMultiple-Dimension Rules

1 2.3 15 10 6.1 2.46 0.892 10.5 10 2 7.8 1.28 1.103 6.2 20 12 14.5 1.38 0.464 15.6 8 5 10.2 0.78 - 0.44

Operation TimeTime at Remaining Number ofEngine to Due Date Operations Shop Time

Job Lathe (hr) (Days) Remaining Remaining CR S/RO

CR Sequence = 4 - 2 - 3 - 1S/RO Sequence = 4 - 3 - 1 - 2

Avg Flow Time 17.175 16.100 26.175 27.150 24.025Avg Early Time 3.425 6.050 0 0 0Avg Past Due 7.350 8.900 12.925 13.900 10.775Avg WIP 1.986 1.861 3.026 3.129 2.777Avg Total Inv 2.382 2.561 3.026 3.129 2.777

Shortest Slack perProcessing Earliest Critical Remaining

FCFS Time Due Date Ratio Operation

Priority Rule Summary

Example 17.2

SequencingSequencingJohnson’s Rule

SequencingSequencingJohnson’s Rule

Time (hr)

Motor Workstation 1 Workstation 2

M1 12 22M2 4 5M3 5 3M4 15 16M5 10 8

Example 17.3

SequencingSequencingJohnson’s Rule

Time (hr)

Motor Workstation 1 Workstation 2

M1 12 22M2 4 5M3 5 3M4 15 16M5 10 8

Sequence =

Example 17.3

SequencingSequencingJohnson’s Rule

Time (hr)

Motor Workstation 1 Workstation 2

M1 12 22M2 4 5M3 5 3M4 15 16M5 10 8

Sequence =

Example 17.3

SequencingSequencingJohnson’s Rule

Time (hr)

Motor Workstation 1 Workstation 2

M1 12 22M2 4 5M3 5 3M4 15 16M5 10 8

Sequence = M3

Example 17.3

SequencingSequencingJohnson’s Rule

Time (hr)

Motor Workstation 1 Workstation 2

M1 12 22M2 4 5M3 5 3M4 15 16M5 10 8

Sequence = M3

Example 17.3

SequencingSequencingJohnson’s Rule

Time (hr)

Motor Workstation 1 Workstation 2

M1 12 22M2 4 5M3 5 3M4 15 16M5 10 8

Sequence = M3

Example 17.3

SequencingSequencingJohnson’s Rule

Time (hr)

Motor Workstation 1 Workstation 2

M1 12 22M2 4 5M3 5 3M4 15 16M5 10 8

Sequence = M3

Example 17.3

SequencingSequencingJohnson’s Rule

Time (hr)

Motor Workstation 1 Workstation 2

M1 12 22M2 4 5M3 5 3M4 15 16M5 10 8

Sequence = M2 M3

Example 17.3

SequencingSequencingJohnson’s Rule

Time (hr)

Motor Workstation 1 Workstation 2

M1 12 22M2 4 5M3 5 3M4 15 16M5 10 8

Sequence = M2 M3

Example 17.3

SequencingSequencingJohnson’s Rule

Time (hr)

Motor Workstation 1 Workstation 2

M1 12 22M2 4 5M3 5 3M4 15 16M5 10 8

Sequence = M2 M3

Example 17.3

SequencingSequencingJohnson’s Rule

Time (hr)

Motor Workstation 1 Workstation 2

M1 12 22M2 4 5M3 5 3M4 15 16M5 10 8

Sequence = M2 M3M5 -

Example 17.3

SequencingSequencingJohnson’s Rule

Time (hr)

Motor Workstation 1 Workstation 2

M1 12 22M2 4 5M3 5 3M4 15 16M5 10 8

Sequence = M2 M3M5 -

Example 17.3

SequencingSequencingJohnson’s Rule

Time (hr)

Motor Workstation 1 Workstation 2

M1 12 22M2 4 5M3 5 3M4 15 16M5 10 8

Sequence = M1M2 M3M5 --

Example 17.3

SequencingSequencingJohnson’s Rule

Time (hr)

Motor Workstation 1 Workstation 2

M1 12 22M2 4 5M3 5 3M4 15 16M5 10 8

Sequence = M1M2 M3M5 --

Example 17.3

SequencingSequencingJohnson’s Rule

Time (hr)

Motor Workstation 1 Workstation 2

M1 12 22M2 4 5M3 5 3M4 15 16M5 10 8

Sequence = M1M2 M3M4 M5 -- - -

Example 17.3

SequencingSequencingJohnson’s Rule

Time (hr)

Motor Workstation 1 Workstation 2

M1 12 22M2 4 5M3 5 3M4 15 16M5 10 8

Sequence = M1M2 M3M4 M5 -- - -

Example 17.3

SequencingSequencingJohnson’s Rule

Time (hr)

Motor Workstation 1 Workstation 2

M1 12 22M2 4 5M3 5 3M4 15 16M5 10 8

Sequence = M1M2 M3M4 M5 -- - -

Workstation

0 5 10 15 20 25 30Day

35 40 45 50 55 60 65

2

1

Example 17.3

SequencingSequencingJohnson’s Rule

Time (hr)

Motor Workstation 1 Workstation 2

M1 12 22M2 4 5M3 5 3M4 15 16M5 10 8

Sequence = M1M2 M3M4 M5 -- - -

Workstation

M2 (4)

M1 (12)

M4 (15)

M5 (10)

M3 (5)

Idle—available for further work

0 5 10 15 20 25 30Day

35 40 45 50 55 60 65

2

1

Example 17.3

SequencingSequencingJohnson’s Rule

Time (hr)

Motor Workstation 1 Workstation 2

M1 12 22M2 4 5M3 5 3M4 15 16M5 10 8

Sequence = M1M2 M3M4 M5 -- - -

Workstation

M2 (4)

M1 (12)

M4 (15)

M5 (10)

M3 (5)

Idle—available for further work

0 5 10 15 20 25 30Day

35 40 45 50 55 60 65

2

1

Example 17.3

SequencingSequencingJohnson’s Rule

Time (hr)

Motor Workstation 1 Workstation 2

M1 12 22M2 4 5M3 5 3M4 15 16M5 10 8

Sequence = M1M2 M3M4 M5 -- - -

Workstation

M2 (4)

M1 (12)

M4 (15)

M5 (10)

M3 (5)

Idle—available for further work

0 5 10 15 20 25 30Day

35 40 45 50 55 60 65

Idle2

1

Example 17.3

SequencingSequencingJohnson’s Rule

Time (hr)

Motor Workstation 1 Workstation 2

M1 12 22M2 4 5M3 5 3M4 15 16M5 10 8

Sequence = M1M2 M3M4 M5 -- - -

Workstation

M2 (4)

M1 (12)

M4 (15)

M5 (10)

M3 (5)

Idle—available for further work

0 5 10 15 20 25 30Day

35 40 45 50 55 60 65

Idle2 M2 (5)

1

Example 17.3

SequencingSequencingJohnson’s Rule

Time (hr)

Motor Workstation 1 Workstation 2

M1 12 22M2 4 5M3 5 3M4 15 16M5 10 8

Sequence = M1M2 M3M4 M5 -- - -

Workstation

M2 (4)

M1 (12)

M4 (15)

M5 (10)

M3 (5)

Idle—available for further work

0 5 10 15 20 25 30Day

35 40 45 50 55 60 65

Idle2 M2 (5)

1

Example 17.3

SequencingSequencingJohnson’s Rule

Time (hr)

Motor Workstation 1 Workstation 2

M1 12 22M2 4 5M3 5 3M4 15 16M5 10 8

Sequence = M1M2 M3M4 M5 -- - -

Workstation

M2 (4)

M1 (12)

M4 (15)

M5 (10)

M3 (5)

Idle—available for further work

0 5 10 15 20 25 30Day

35 40 45 50 55 60 65

Idle2 M2 (5) Idle

1

Example 17.3

SequencingSequencingJohnson’s Rule

Time (hr)

Motor Workstation 1 Workstation 2

M1 12 22M2 4 5M3 5 3M4 15 16M5 10 8

Sequence = M1M2 M3M4 M5 -- - -

Workstation

M2 (4)

M1 (12)

M4 (15)

M5 (10)

M3 (5)

Idle—available for further work

0 5 10 15 20 25 30Day

35 40 45 50 55 60 65

Idle2 M2 (5)

M1 (22)Idle

1

Example 17.3

SequencingSequencingJohnson’s Rule

Time (hr)

Motor Workstation 1 Workstation 2

M1 12 22M2 4 5M3 5 3M4 15 16M5 10 8

Sequence = M1M2 M3M4 M5 -- - -

Workstation

M2 (4)

M1 (12)

M4 (15)

M5 (10)

M3 (5)

Idle—available for further work

0 5 10 15 20 25 30Day

35 40 45 50 55 60 65

Idle2 M2 (5)

M1 (22)

M4 (16)Idle

1

Example 17.3

SequencingSequencingJohnson’s Rule

Time (hr)

Motor Workstation 1 Workstation 2

M1 12 22M2 4 5M3 5 3M4 15 16M5 10 8

Sequence = M1M2 M3M4 M5 -- - -

Workstation

M2 (4)

M1 (12)

M4 (15)

M5 (10)

M3 (5)

Idle—available for further work

0 5 10 15 20 25 30Day

35 40 45 50 55 60 65

Idle2 M2 (5)

M1 (22)

M4 (16)

M5 (8)Idle

1

Example 17.3

SequencingSequencingJohnson’s Rule

Time (hr)

Motor Workstation 1 Workstation 2

M1 12 22M2 4 5M3 5 3M4 15 16M5 10 8

Sequence = M1M2 M3M4 M5 -- - -

Workstation

M2 (4)

M1 (12)

M4 (15)

M5 (10)

M3 (5)

Idle—available for further work

0 5 10 15 20 25 30Day

35 40 45 50 55 60 65

Idle2 M2 (5)

M1 (22)

M4 (16)

M5 (8)

M3 (3)Idle

1

Example 17.3

SequencingSequencingJohnson’s Rule

Time (hr)

Motor Workstation 1 Workstation 2

M1 12 22M2 4 5M3 5 3M4 15 16M5 10 8

Sequence = M1M2 M3M4 M5 -- - -

Workstation

M2 (4)

M1 (12)

M4 (15)

M5 (10)

M3 (5)

Idle—available for further work

0 5 10 15 20 25 30Day

35 40 45 50 55 60 65

Idle2 M2 (5)

M1 (22)

M4 (16)

M5 (8)

M3 (3)Idle

1

Example 17.3

Theory of ConstraintsTheory of Constraints

Identify the system Identify the system bottleneck(s)bottleneck(s)

Exploit the bottleneck(s)Exploit the bottleneck(s) Subordinate all other Subordinate all other

decisions to step 2decisions to step 2 Elevate the bottleneck(s)Elevate the bottleneck(s) Don’t let inertia set inDon’t let inertia set in

Scheduling ServicesScheduling Services

Scheduling ServicesScheduling Services

Day M T W Th F S Su

Number of employees 6 4 8 9 10 3 2

Required employeesExample 17.4

Scheduling ServicesScheduling Services

Day M T W Th F S Su

Number of employees 6 4 8 9 10 3 2Employee 1

Required employeesExample 17.4

Scheduling ServicesScheduling Services

Day M T W Th F S Su

Number of employees 6 4 8 9 10 3 2Employee 1 X X X X X

Required employeesExample 17.4

Scheduling ServicesScheduling Services

Day M T W Th F S Su

Number of employees 6 4 8 9 10 3 2Employee 1 X X X X X

Requirement 5 3 7 8 9 3 2

Required employeesExample 17.4

Scheduling ServicesScheduling Services

Day M T W Th F S Su

Number of employees 6 4 8 9 10 3 2Employee 1 X X X X X

Requirement 5 3 7 8 9 3 2Employee 2 X X X X X

Required employeesExample 17.4

Scheduling ServicesScheduling Services

Day M T W Th F S Su

Number of employees 6 4 8 9 10 3 2Employee 1 X X X X X

Requirement 5 3 7 8 9 3 2Employee 2 X X X X X

Requirement 4 2 6 7 8 3 2

Required employeesExample 17.4

Scheduling ServicesScheduling Services

Day M T W Th F S Su

Number of employees 6 4 8 9 10 3 2Employee 1 X X X X X

Requirement 5 3 7 8 9 3 2Employee 2 X X X X X

Requirement 4 2 6 7 8 3 2Employee 3 X X X X X

Required employeesExample 17.4

Scheduling ServicesScheduling Services

Day M T W Th F S Su

Number of employees 6 4 8 9 10 3 2Employee 1 X X X X X

Requirement 5 3 7 8 9 3 2Employee 2 X X X X X

Requirement 4 2 6 7 8 3 2Employee 3 X X X X X

Requirement 3 1 5 6 7 3 2

Required employeesExample 17.4

Scheduling ServicesScheduling Services

Day M T W Th F S Su

Number of employees 6 4 8 9 10 3 2Employee 1 X X X X X

Requirement 5 3 7 8 9 3 2Employee 2 X X X X X

Requirement 4 2 6 7 8 3 2Employee 3 X X X X X

Requirement 3 1 5 6 7 3 2Employee 4 X X X X X

Required employeesExample 17.4

Scheduling ServicesScheduling Services

Day M T W Th F S Su

Number of employees 6 4 8 9 10 3 2Employee 1 X X X X X

Requirement 5 3 7 8 9 3 2Employee 2 X X X X X

Requirement 4 2 6 7 8 3 2Employee 3 X X X X X

Requirement 3 1 5 6 7 3 2Employee 4 X X X X X

Requirement 3 1 4 5 6 2 1

Required employeesExample 17.4

Scheduling ServicesScheduling Services

Day M T W Th F S Su

Number of employees 6 4 8 9 10 3 2Employee 1 X X X X X

Requirement 5 3 7 8 9 3 2Employee 2 X X X X X

Requirement 4 2 6 7 8 3 2Employee 3 X X X X X

Requirement 3 1 5 6 7 3 2Employee 4 X X X X X

Requirement 3 1 4 5 6 2 1Employee 5 X X X X X

Required employeesExample 17.4

Scheduling ServicesScheduling Services

Day M T W Th F S Su

Requirement 2 0 3 4 5 2 1

Required employeesExample 17.4

Scheduling ServicesScheduling Services

Day M T W Th F S Su

Requirement 2 0 3 4 5 2 1Employee 6 X X X X X

Required employeesExample 17.4

Scheduling ServicesScheduling Services

Day M T W Th F S Su

Requirement 2 0 3 4 5 2 1Employee 6 X X X X X

Requirement 2 0 2 3 4 1 0Employee 7 X X X X X

Required employeesExample 17.4

Scheduling ServicesScheduling Services

Day M T W Th F S Su

Requirement 2 0 3 4 5 2 1Employee 6 X X X X X

Requirement 2 0 2 3 4 1 0Employee 7 X X X X X

Requirement 1 0 1 2 3 1 0Employee 8 X X X X X

Required employeesExample 17.4

Scheduling ServicesScheduling Services

Day M T W Th F S Su

Requirement 2 0 3 4 5 2 1Employee 6 X X X X X

Requirement 2 0 2 3 4 1 0Employee 7 X X X X X

Requirement 1 0 1 2 3 1 0Employee 8 X X X X X

Requirement 0 0 0 1 2 1 0Employee 9 X X X X X

Required employeesExample 17.4

Scheduling ServicesScheduling Services

Day M T W Th F S Su

Requirement 2 0 3 4 5 2 1Employee 6 X X X X X

Requirement 2 0 2 3 4 1 0Employee 7 X X X X X

Requirement 1 0 1 2 3 1 0Employee 8 X X X X X

Requirement 0 0 0 1 2 1 0Employee 9 X X X X X

Requirement 0 0 0 0 1 0 0Employee 10 X X X X X

Required employeesExample 17.4

Scheduling ServicesScheduling Services

Day M T W Th F S Su

Employee 1 X X X X X off off

Employee 2 X X X X X off off

Employee 3 X X X X X off off

Employee 4 off off X X X X XEmployee 5 X X X X X off off

Employee 6 off off X X X X XEmployee 7 X X X X X off off

Employee 8 X X X X X off off

Employee 9 off X X X X X off

Employee 10 X X X X X off off

Final ScheduleExample 17.4

Scheduling ServicesScheduling Services

Day M T W Th F S Su

Employee 1 X X X X X off off

Employee 2 X X X X X off off

Employee 3 X X X X X off off

Employee 4 off off X X X X XEmployee 5 X X X X X off off

Employee 6 off off X X X X XEmployee 7 X X X X X off off

Employee 8 X X X X X off off

Employee 9 off X X X X X off

Employee 10 X X X X X off off

Final Schedule

Day M T W Th F S Su

Example 17.4

Scheduling ServicesScheduling Services

Day M T W Th F S Su

Employee 1 X X X X X off off

Employee 2 X X X X X off off

Employee 3 X X X X X off off

Employee 4 off off X X X X XEmployee 5 X X X X X off off

Employee 6 off off X X X X XEmployee 7 X X X X X off off

Employee 8 X X X X X off off

Employee 9 off X X X X X off

Employee 10 X X X X X off off

Final Schedule

Day M T W Th F S Su

Capacity, C 7 7 10 10 10 3 2

Example 17.4

Scheduling ServicesScheduling Services

Day M T W Th F S Su

Employee 1 X X X X X off off

Employee 2 X X X X X off off

Employee 3 X X X X X off off

Employee 4 off off X X X X XEmployee 5 X X X X X off off

Employee 6 off off X X X X XEmployee 7 X X X X X off off

Employee 8 X X X X X off off

Employee 9 off X X X X X off

Employee 10 X X X X X off off

Final Schedule

Day M T W Th F S Su

Capacity, C 7 7 10 10 10 3 2Requirements, R 6 4 8 9 10 3 2

Example 17.4

Scheduling ServicesScheduling Services

Day M T W Th F S Su

Employee 1 X X X X X off off

Employee 2 X X X X X off off

Employee 3 X X X X X off off

Employee 4 off off X X X X XEmployee 5 X X X X X off off

Employee 6 off off X X X X XEmployee 7 X X X X X off off

Employee 8 X X X X X off off

Employee 9 off X X X X X off

Employee 10 X X X X X off off

Final Schedule

Day M T W Th F S Su

Capacity, C 7 7 10 10 10 3 2Requirements, R 6 4 8 9 10 3 2Slack, C - R 1 3 2 1 0 0 0

Example 17.4