Using Discrete Event Simulation to Improve Diagnostic Imaging Resource Utilization

Using Discrete Event Simulation to Improve Diagnostic Imaging Resource Utilization

Pheba PhilipAshley Robinson

June 2014

MD Anderson & the Breast Diagnostic Center

Problem & Aim Statement

Simulation Preparation

Building the Simulation

Initial Results

Next Steps

Challenges

Outline

Background on MD Anderson

Located in Houston, TX

Found in 1941

20,000 Employees (1,600 faculty)

650 inpatient beds

1.3 M outpatient visits

Provided care to 120,000 patients in 2013

Ranked Number 1 in cancer care by U.S. News and World Report

Background Breast Diagnostic Imaging

Sub-specialty of the Department of Diagnostic Radiology

Biopsies performed and Images taken of the breast to identify cancer

Over 54,000 procedure performed

Why use Simulation?

• Understanding of complex systems

• Identification of constraints in the system (patient flow, staff utilization, resource management)

• Testing & experimentation

• Visual tool to enhance communication

• FlexSim Healthcare used for the simulation model

Problem & Aim Statement

Patients are experiencing long wait times and resources are under utilized in the breast diagnostic center.

The aim is to build a simulation model that identifies opportunities to reduce patient wait time and better utilize resources by April 2014.

SIMULATION PREPARATION


Identify the Scope

1. Wait time of patients with appointments in Mammo and US

2. Utilization of labor and equipment

3. Scheduling of patients, radiologist, and techs

Center Information

• Two Modalities: Diagnostic Mammo & Ultrasound (US)

• 9 US Techs / 9 Mammo Techs

• 3 US Radiologist / 2 Diagnostic Mammo Radiologist

• 2 Diagnostic Assistants

• 3 RNs

• 8 Breast US Rooms/ 8 Diagnostic Mammo Rooms


Four Patient Flow Charts

• Diagnostic Mammo

• Ultrasound

• Diagnostic to Mammo

• Stereotactic



Process Flow

Activities captured for

• Electronic Data Validation

• Simulation


Data Collection

34% 42% 24%

Baseline 63.4 (min)

Data Collection


Data Collection


BUILDING THE SIMULATION


Insert the schedule of all labor resources

represented in the model


Wait Area

Entrance & ExitRadiologist Reading Room

Diagnostic Mammo

Ultrasound

Diagnostic Mammo

Patient Path

Initial Results

Next Steps

• Validate simulation results

• Recommend changes based on simulation output

• Create new simulation with recommended changes

Before you begin…

• What are you simulating?

• Are you simulating something you can’t change?

• Are you attempting to simulate EVERYTHING? EEK!

• Validate, Validate, VALIDATE

Supplementary

MD Anderson Volume of Clinical Activity2

SupplementaryModality Description

X-rays Common method of sending beams to

be absorbed through the body to

creating images

Magnetic Resonance Imaging (MRI) Accurate test that uses a magnetic field

to make computer images of the body’s

soft tissue, large blood vessels and

major organs

Computed Tomography (CT) Scan Test that uses radiographic beams to

make detailed computerized pictures

taken with a special X-ray machine;

more precise than a standard X-ray

Mammography An x-ray image specifically of the

breast for both screening and

diagnostic purposes

Nuclear medicine Specialized technology that uses

radioactive materials

(radiopharmaceuticals) in diagnosis

and therapy

Positron Emission Tomography (PET) Similar to a CT Scan, but patient takes

a small dose of radioactive sugar which

provides information about tissue

function

Ultrasound High-frequency sound waves

transmitted into the body and

converted into a computerized image to

determine if a suspicious lump is solid

or fluid.

SupplementaryUltrasound Procedures Mammography Procedures

Ultrasound Guided Needle Biopsy Mammography, Ductography

/Galactography, SIN S&I or Multiple

Ultrasound Pre-op Needle

Localization

Unilateral Digital Screen Mammogram

and/or with TOMO

US, Breast with Fine Needle

Aspiration

Unilat Digital Screen Mammogram

with implant and/or with TOMO

US, Radiation Seed 76942 Digital Screening Mammogram and/or

with TOMO

Intra-operative Ultrasound Digital Screening mammogram with

implants and/or with TOMO

Ultrasound Breast Unilateral Digital Bilateral Diag Mammogram

and/or with TOMO

Ultrasound Breast Bilateral Digital Unilateral Diag Mammogram

and/or with TOMO

Ultrasound Chest Mammogram Guide For Needle

Placement

Ultrasound, Extremity Limited Mammogram guided Seed

Localization

Molecular Breast Imaging

- Key Stats- LOS- Average Wait Times- Volumes- Operating Hours (closing time)- Evaluation- Modality concerns- Bottlenecks?- Space Sufficient?- Utilization- What-If Scenarios

Projected Demand

DI Processes & Service Times

Facility Layout

Simulation Model

Supplementary

Using Discrete Event Simulation to Improve Diagnostic Imaging Resource Utilization

Documents

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