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Mark Murray MD, MPA
Mark Murray & Associates2209 Capitol Ave
Sacramento, CA 95816916-441-3070
Big System Flow
The problem ED overcrowding Hospital overcrowding Diversions—external and internal LWBS Cancellations, particularly of elective
surgical cases Variable utilization Cost and revenue implications with the
variation
Introverted/introspection Flow system dynamics and gravity Customer flow- value stream Horizontal/vertical Effective, efficient and satisfying Demand, supply, activity, gap &
variation System Optimize
Basic Dynamic
Demand/Supply Dynamic
Variation
Terms Demand: workload generated within a
specified time frame Activity: work done within a specified time
frame Supply: “worker” (person or machine) set
aside to do the work within the specified time frame
Backlog: work in progress, work waiting to be completed, wait list, queue, inventory, warehouse
Constraint/bottleneck: rate-limiting step
Why focus on delay? Delay results from a mismatch either
temporary or permanent of demand and supply
Delays lead to dissatisfaction Delays sub-optimize revenue Delays adversely effect clinical outcomes Delays cost money Delays represent system inefficiency We can only go as fast as the slowest step Perception that delay=lack of resource
Why do queues form? Demand > Supply Variation Paradigm Buffer for revenue, for predictability
and for assurance of 100% utilization (false productivity)
Demand > capacity
Time
waiting numbersIf Demand
> Activity or Capacity
Levels or types of variation
Volume
Arrivals
Process time
Variation
Within Day
Between Day
Demand & capacity for breast clinic
0
20
40
60
Week
Number
3 January 2000 22nd January 2001
Total number of patients referred
Number of clinic slots available
Sources of demand variation
Variation in volume (between day variation)
Random arrivals (within day variation)
Randomness of clinical condition/acuity/time- handling time
Randomness of internally generated demand (electives)
Sources of supply variation Relative lack of any of the
converging supply components Pattern of supply components Carve outs or priorities that restrict
flexibility
Moment of truth Even if the average demand =
average supply The variation of demand + the
variation of supply Will result in a queue Waiting times or delays inevitably
result from system variation
Walter A. Shewart-early 1920’s, Bell Laboratories
While every process displays variation…
some processes display controlled variation stable,consistent pattern of variation constant causes/ “chance” Common cause variation
while others display uncontrolled variation pattern changes over time special cause variation/“assignable”
2 ways to improve a process
If uncontrolled variation: identify special causes (may be good or bad)
process is unstable variation is extrinsic to process cause should be identified and “treated”
If controlled variation: reduce variation, improve outcome
process is stable variation is inherent to process therefore, process must be changed: reduce
steps, increase reliability of each step
Natural Variation:A Stable Process
Upper process
limit
Mean
Lower process
limit
0
10
20
30
40
50
60
70
80
F M A M J J A S O N D J F M A M J J A S O N D
Special Cause Variation
0
10
20
30
40
50
60
70
80
90
F M A M J J A S O N D J F M A M J J A S O N D
Variation and Predictability Which demand stream is more
variable- planned or unplanned?
Which demand stream is more predictable planned or unplanned?
Know and manage variation Natural/unplanned Results from the natural rate at which
illness brings patients into the hospital Influenced by level of health, prevention,
early detection Artificial/planned This pattern results from behavior of
people, processes or systems This variation is theoretically controllable
Vicious cycle Variation in demand or in supply create a
delay The wait time creates a need to prioritize Prioritization leads to inflexibility and more
variation More waits Assumption that demand is greater than
supply Addition of more supply Adds more variation
Variation Variation is ubiquitous Variation is not measured More variation in planned than
unplanned Demand = Volume x LOS So variation has a long-term effect
over days, not a single effect as a single incident
What does the patient see?
Linear Flow
D D S D S D S D S D S
Step 1 Step 2 Step 3 Step 4 Step 5
Delay Delay Delay Delay Delay
What do we see?
Vertical Flow Filter
C
A
Appointment Template Filter
New ReturnConsultProcedurePost-surgeryReturn-long
Return-shortNew-longNew-shortConsult-longConsult-short
Office Manager Filter
Office OR Call Admin Off
What we see Today’s schedules of supply to
match the various demand streams Response to the demand streams Waits for single isolated patients,
not the sum of waits for that patient Waits after us, not in front of us
What we don’t see The demand streams The wait in each of the demand
streams The wait at each step The patients horizontal journey The three dimensional view
DaysDelay
External Demand
Delay Delay Delay Delay Delay
PC SC Test/ SurgeryProcedure
Hospital Followup
A
B
C
D
A
• Supply lines that match demand stream
Vertical/HorizontalDays
Cancer Center flow-map
Test
SC Surgery
Discharge
External Demand
PC Bed
MDTOncology
Radiation
Chemo
Follow up
Test
Test
Follow up
Internal Demand
Inte
rnal
Dem
and
Test
MDT
Medical Flow
Test
SCHospital
ED
Post hospital venue
Procedure
PC
ICU
Return
Test
Surgery Flow
Test
SCSurgery
ED
Bed
Internal Demand
External Demand
ICU
PC
Follow up
Discharge
HOSPITAL FLOORICU/CCUAdvanced Care
Other Places
MENTALHEALTH
WORLD
SPECIALTY CARE
ED
PRIMARY CARE
HOME
SURGERY
DiagnosticTests
PACU
PREP
Emergency Department Patient Flow
ENTRYWALK-INS EMS
Admission Desk (admission representative) greeting according to script record created: complaint, DOB, PCP, ED provider triage by level of acuity RN notified verbally or with call light to complete triage in triage room
Lev
el 1
, 2
Exam Room (RN, AR, MD) patient transferred to room immediately with record RN/provider assessment AR registration in room when notified
or RN if not done immediately
RN expanded assessment protocols initiated/completed bedside diagnostics completed nursing care delivery model
Provider Assessment/Exam tests ordered treatment reassessment disposition dictate discharge or more likely transfer
Triage Room (RN, AR) RN completes triage, establishes level of acuity Diagnostics per standing order initiated Allergy band applied Room assigned if available AR notified
AR completes registration in triage room Welcome packet explained ID band applied Patient escorted to exam room or family room
Level 1, 2
Exam Room (RN, AR, MD) AR follows script, phone, call light, blanket,transfer, give gown, close curtain and door sticker to green patient sheet at house station write c.c. on patient tracking board chart to new patient arrival basket according to triage
RN Expanded Assessment protocols initiated/completed bedside diagnostics completed nursing care delivery model chart to MD rack
Provider Assessment/Exam tests ordered treatment disposition dictate chart to rack
Discharge HIS notes completed/shared with patient Disposition per Priority Referral Follow up with PCP Patient escorted from ED
Family Room
Transfer
RN follow-upper P & P
Tests&
Diagnostics
Tests
What do we learn? The system is complex with at least 3
dimensions The patients move horizontally, we think
vertically Supply allocation decisions, made on
instinct, have huge system effects There is a great deal of variation in both
demand and in supply at each step Variation is amplified as we move Queues are a result of a permanent or
temporary mismatch of demand and supply
What else do we learn? Patients move from one warehouse to
another There is always a constraint We are blind at the intersections Carve out or priority makes the queues
worse, not better Increasing supply does not always work,
the delays remain but just get moved
Process for Improvement Team Aim Map Change Measure - Principles -Strategies Measure again
Our Task in Flow Improvement Flow map the customer flow process: input,
throughput, output Use a process for improvement: team, aim, change and
measure Use a set of change principles at & between each step Measure: delay for and at each step, DSA,variation Achieve a balance of demand and supply at every step
with change strategies (change strategy: balance) Reduce the variation in both demand and supply at
every step ( change strategy: contingency plans ) Identify common and special causes of variation Be flexible on the supply side Address the system constraint first Create the correct linkages
Apply High Leverage Changes within and between each step
Balance upstream and downstream demand and supply for all services
Eliminate any backlogs of work Reduce the queues from one entity to another Develop contingency plans to address all variation Reduce demand Identify and manage each supply constraint Synchronize the work Predict and anticipate needs Optimize the environment: equipment, staff and
space
Change ideas Each step (node) needs to be
optimized The interface between steps needs
to be optimized Focus on the “system” flow
constraint either between or within the steps
Constraints will shift
