Basic Queue Theory and Gantt Charts

Steve HarrisonWednesday 20th January 2014Seminar Room 2 MEC

Basic Queue Theory and Gantt Charts

Topics

• Variation – A recap

• Basic Queue theory

• Gantt Charts – Process Building Blocks

• Other Variation Concepts

“If I had to reduce my message for management to just a few words, I’d say it all had to do with reducing variation.”

W. Edwards Deming

Variation – what to do?

5

Common Cause Variation

Reduce variation: Increase precision - make the process even more reliable.

Not satisfied with median performance (result): Redesign process to get a better result

Special Cause Variation

Identify the Cause: If Positive: Maximise, optimise, replicate, standardise. If Negative: Minimise, eliminate.

6

Application – Responding to Variation

Variation and Queues

Variation & Queues

Consecutive Patients

Pro

cedu

re T

ime

(Min

utes

)

50%

100% 80%

80% rule is the most efficient balancing waiting and waste

How to calculate

• =(((Max – Min)/100)*80 )+ Min

• 23 – 7 = 16

• 16/100 = 0.16

• 0.16*80 = 12.8

• 12.8 + 7 = 19.8

• 19.8 approx 20mins

Plan Cycle Time = 20m

Role Cycle Time at 80%

Lung Function 15m

Weight & Nurse 10m

Dietician 20m

Dr 20m

Others 15m

Cycle time at 80% - PDSA 1M

ore

Var

iabl

e

Mor

e R

elia

ble

1.15 1.30 2.00 2.30 3.00 3.30 4.00 4.30 5.00

Patient 1L L L W N D D D D Dr Dr Dr Dr O O O

Patient 2L L L W N D D D D Dr Dr Dr Dr O O O

Patient 3L L L W N D D D D Dr Dr Dr Dr O O O

Patient 4L L L W N D D D D Dr Dr Dr Dr O O O

Patient 5L L L W N D D D D Dr Dr Dr Dr O O O

Patient 6L L L W N D D D D Dr Dr Dr Dr O O O

Patient 7L L L W N D D D D Dr Dr Dr Dr O O O

Patient 8L L L W N D D D D Dr Dr Dr Dr O O O

Patient 9L L L W N D D D D Dr Dr Dr Dr O O O

Patient 10L L L W N D D D D Dr Dr Dr Dr O O O

Patient 11L L L W N D D D D Dr Dr Dr Dr O O O

Patient 12L L L W N D D D D Dr Dr Dr Dr O O O

Patient 13L L L W N D D D D Dr Dr Dr Dr O O O

Patient 14L L L W N D D D D Dr Dr Dr Dr O O O

Patient 15L L L W N D D D D Dr Dr Dr Dr O O O

Patient 16L L L W N D D D D Dr Dr Dr Dr O O O

Patient 17L L L W N D D D D Dr Dr Dr Dr O O O

Patient 18L L L W N D D D D Dr Dr Dr Dr O O O

1.15 1.30 2.00 2.30 3.00 3.30 4.00 4.30 5.00

Patient 1L L L W N D D D D Dr Dr Dr Dr O O O

Patient 2L L L W N D D D D Dr Dr Dr Dr O O O

Patient 3L L L W N D D D D Dr Dr Dr Dr O O O

Patient 4L L L W N D D D D Dr Dr Dr Dr O O O

Patient 5L L L W N D D D D Dr Dr Dr Dr O O O

Patient 6L L L W N D D D D Dr Dr Dr Dr O O O

Patient 7L L L W N D D D D Dr Dr Dr Dr O O O

Patient 8L L L W N D D D D Dr Dr Dr Dr O O O

Patient 9L L L W N D D D D Dr Dr Dr Dr O O O

Patient 10L L L W N D D D D Dr Dr Dr Dr O O O

Patient 11L L L W N D D D D Dr Dr Dr Dr O O O

Patient 12L L L W N D D D D Dr Dr Dr Dr O O O

Patient 13L L L W N D D D D Dr Dr Dr Dr O O O

Patient 14L L L W N D D D D Dr Dr Dr Dr O O O

Patient 15L L L W N D D D D Dr Dr Dr Dr O O O

Patient 16L L L W N D D D D Dr Dr Dr Dr O O O

Patient 17L L L W N D D D D Dr Dr Dr Dr O O O

Patient 18L L L W N D D D D Dr Dr Dr Dr O O O

1.15 1.30 2.00 2.30 3.00 3.30 4.00 4.30 5.00

Patient 1L L L W N D D D D Dr Dr Dr Dr O O O

Patient 2L L L W N D D D D Dr Dr Dr Dr O O O

Patient 3L L L W N D D D D Dr Dr Dr Dr O O O

Patient 4L L L W N D D D D Dr Dr Dr Dr O O O

Patient 5L L L W N D D D D Dr Dr Dr Dr O O O

Patient 6L L L W N D D D D Dr Dr Dr Dr O O O

Patient 7L L L W N D D D D Dr Dr Dr Dr O O O

Patient 8L L L W N D D D D Dr Dr Dr Dr O O O

Patient 9L L L W N D D D D Dr Dr Dr Dr O O O

Patient 10L L L W N D D D D Dr Dr Dr Dr O O O

Patient 11L L L W N D D D D Dr Dr Dr Dr O O O

Patient 12L L L W N D D D D Dr Dr Dr Dr O O O

Patient 13L L L W N D D D D Dr Dr Dr Dr O O O

Patient 14L L L W N D D D D Dr Dr Dr Dr O O O

Patient 15L L L W N D D D D Dr Dr Dr Dr O O O

Patient 16L L L W N D D D D Dr Dr Dr Dr O O O

Patient 17L L L W N D D D D Dr Dr Dr Dr O O O

Patient 18L L L W N D D D D Dr Dr Dr Dr O O O

1.15 1.30 2.00 2.30 3.00 3.30 4.00 4.30 5.00

Patient 1L L L W N D D D D Dr Dr Dr Dr O O O

Patient 2L L L W N D D D D Dr Dr Dr Dr O O O

Patient 3L L L W N D D D D Dr Dr Dr Dr O O O

Patient 4L L L W N D D D D Dr Dr Dr Dr O O O

Patient 5L L L W N D D D D Dr Dr Dr Dr O O O

Patient 6L L L W N D D D D Dr Dr Dr Dr O O O

Patient 7L L L W N D D D D Dr Dr Dr Dr O O O

Patient 8L L L W N D D D D Dr Dr Dr Dr O O O

Patient 9L L L W N D D D D Dr Dr Dr Dr O O O

Patient 10L L L W N D D D D Dr Dr Dr Dr O O O

Patient 11L L L W N D D D D Dr Dr Dr Dr O O O

Patient 12L L L W N D D D D Dr Dr Dr Dr O O O

Patient 13L L L W N D D D D Dr Dr Dr Dr O O O

Patient 14L L L W N D D D D Dr Dr Dr Dr O O O

Patient 15L L L W N D D D D Dr Dr Dr Dr O O O

Patient 16L L L W N D D D D Dr Dr Dr Dr O O O

Patient 17L L L W N D D D D Dr Dr Dr Dr O O O

Patient 18L L L W N D D D D Dr Dr Dr Dr O O O

PDSA - Plan

PDSA - Plan1.15 1.30 2.00 2.30 3.00 3.30 4.00 4.30 5.00

Patient 1L L L W N D D D D Dr Dr Dr Dr O O O

Patient 2L L L W N D D D D Dr Dr Dr Dr O O O

Patient 3L L L W N D D D D Dr Dr Dr Dr O O O

Patient 4L L L W N D D D D Dr Dr Dr Dr O O O

Patient 5L L L W N D D D D Dr Dr Dr Dr O O O

Patient 6L L L W N D D D D Dr Dr Dr Dr O O O

Patient 7L L L W N D D D D Dr Dr Dr Dr O O O

Patient 8L L L W N D D D D Dr Dr Dr Dr O O O

Patient 9L L L W N D D D D Dr Dr Dr Dr O O O

Patient 10L L L W N D D D D Dr Dr Dr Dr O O O

Patient 11L L L W N D D D D Dr Dr Dr Dr O O O

Patient 12L L L W N D D D D Dr Dr Dr Dr O O O

Patient 13L L L W N D D D D Dr Dr Dr Dr O O O

Patient 14L L L W N D D D D Dr Dr Dr Dr O O O

Patient 15L L L W N D D D D Dr Dr Dr Dr O O O

Patient 16L L L W N D D D D Dr Dr Dr Dr O O O

Patient 17L L L W N D D D D Dr Dr Dr Dr O O O

Patient 18L L L W N D D D D Dr Dr Dr Dr O O O

PDSA – Do & Study

Cystic Fibrosis

Redesign - Treating the System

Clinic redesigned to new template shown below.

Follow Up frequency by band standardised - PDSA to help

increase capacity and meet growing demand

US Microsystems work focused team onto Adherence

Waiting reduced from mean of 40

mins to 8 mins

Improvements in clinic flow and pa-

tient experience also had a positive

effect on DNA rate for the service,

reducing rate from 16.3% to 8.3%

Clinic Redesign

Adherence—making the invisible visible

DNA improvement

Research project initiated into im-

proving adherence considering barri-

ers and evidence based interven-

tions

Remote monitoring of nebulised IVs

downloaded from web –displayed

on run charts to detect changes

Redesign of annual review process. Un-

necessary diagnostic tests and scans re-

moved saving an estimated £15k

Process re ordered as below to reduce

variation and improve the efficiency of the

process.

Reduction in time spent at hospital from a

full day to a half day for most patients

Demand is increasing....

More slots needed...

80% = 21mins

3hrs = 8 Patients

80% = 21mins

3hrs = 8 Patients

80% = 18mins

3hrs = 10 Patients

80% = 21mins

3hrs = 8 Patients

80% = 18mins

3hrs = 10 Patients

80% = 14mins

3hrs = 12 Patients

HOW DO YOU REDUCE COMMON CAUSE VARIATION?

GSM

More Queuing....

Capacity required = 27

Capacity required = 27

Capacity required = 49(5 beds less than separate units ~£400,000)

Lung Cancer Clinic

28

13 + 11 = 24

Lung Cancer - pooled

And Finally - More Queuing....

Which is best?

C Q

C Q

C Q

S

S

S

C Q

S

S

S

C QC Q

And Finally - Which is best?

C Q Long

C QShort

S

S

C QLong

S

S

S

C QShort

C QLong

DISCUSSION

THANKS!