A Lean Six Sigma Case Study

A Lean Six Sigma Case Study

If you want to prosper for a year, grow rice. If you want to prosper for a decade, plant trees. If

you want to prosper for a century, grow people — a wise old farmer reflecting back on a life

of toil in the soil


The following Lean Six Sigma case study will reflect a real-life healthcare problem with

Continuous Improvement and Lean Six Sigma Tools to show how some of the tools are put into

place in the real world. The object of this project is your appropriate use of Lean Six Sigma

tools and the data provided. Project completion is required to pass the course. Project

assignments are assessed on a Complete/Incomplete basis. Each Phase of the DMAIC process in

the Project has an assignment. Assignments must be submitted to the instructor by the end of the

week corresponding to the DMAIC Phase. The exception is the week 8 or Control phase

assignment which needs to be submitted early in the last week of the course to allow grading.

The Instructor will determine if the student has submitted a Project assignment that is Complete.

If the assignment is Incomplete, there will be interaction between the Instructor and student until

the assignment is Complete. All project assignments must be assessed as Complete for the

student to pass the course. An Incomplete project will result in a Failing grade for the course.

Student Case Study

Case Study: Process Improvement – Reduction in Wait Time for Patients in a Doctor Office

Executive Summary Dr. Deasley is a popular Doctor in Tampa, Florida specializing in primary care. He spends a great deal of time with each of his patients, typically, 45 minutes to one (1) hour. As a result, there are many other patients waiting in the waiting room who become impatient at the long wait time. The Doctor has hours every day except Wednesdays. He has Hospital Clinic on Wednesdays and does not have office hours. Dr. Deasley’s office hours are 7:30 AM to 5:30 PM (patients can be scheduled up until 5:30 PM) on Tuesdays and Thursdays and 9:30 AM to 7:30 PM (patients can be scheduled up until 7:30 PM) on Mondays and Fridays. He does Hospital Rounds from 6:00 AM to 8:00 AM. He conducts patient call backs between patients, during his lunch hour and after office hours. We triage the calls so he gets back to more seriously sick patients first. However, sometimes he doesn’t call back non-emergencies until the next AM. Dr. Deasley is becomes overbooked because he likes to have 10 patients scheduled per day. However, due to time constraints he frequently needs to rebook patients he is unable to see due to time constraints.

Dr. Deasley’s patients and staff love him for his patience and attention. But, several long term patients have left his practice because of this issue. This has resulted in a decrease in revenue for the office. In addition, his office is experiencing a rather high rate of staff turnover. Staff are responsible for booking patients and managing the workflow in the office. When backlogs occur and patients become annoyed about wait times, the staff usually experience the brunt of the patient dissatisfaction, which effects staff morale. Each time the office hires replacement staff, it takes a significant amount of time to train new employees and it is costly to advertise and recruit competent staff. Dr. Deasley is very concerned about both his patients and staff.

His Office Manager, Ms. Smith, who recently was employed at Memorial Hospital of Tampa, participated in several Continuous Improvement Projects at the hospital. She is a certified Lean Six Sigma Green Belt. As a result, Ms. Smith has suggested a plan to the doctor to conduct a Lean Six Sigma project with the objective of Reducing Patient Wait Time and Improving Office Workflow. Ms. Smith explained the project improvements and objectives. Dr. Deasley has approved the project. As an initial step, the Office Manager has established her team. Each employee has a role in the project. Based on patient complaints and the doctor’s requirements, they have some initial Voice of Customer (VOC). Patients would like to see the Doctor within 10 minutes of arriving and spend no more than 30 minutes in the office total for routine visits. The Doctor would like to see 15 patients per day. These changes need to be made within 3 months in order to minimize patient dissatisfaction, stop patients leaving the practice due to long wait times and rescheduling and improve employee morale and retention.

Define 1. Complete a Project Charter with all of the required Information

a. Please write the Problem Statement: b. Please write the Goal Statement utilizing S.M.A.R.T. objectives (Specific,

Measureable, Attainable, Relevant and Time Bound): c. What is in Scope? What is out of Scope? d. Who are Key Stakeholders? e. What are key Milestones?

2. Please complete a High Level “As Is” Process Map. 3. Please create a SIPOC of the process based on the information that you know. Feel free to

use your imagination for this. a. Describe methods for collecting Voice of the Customer. (SEE APPENDIX A for VOC)

4. Please create an Affinity Diagram or List based on VOC so you can identify Customer “NEEDS” for CTQ Tree

5. Please create a Critical to Quality Tree utilizing the Voice of the Customer. Identify the Needs, Drivers and Requirements or Metric to needed to meet these needs

Conclusion of Define: The output of the DEFINE stage is a PROJECT CHARTER (PC) and STAKEHOLDER ANALYSIS (SA). The PC shall include a Problem Statement with Goals utilizing S.M.A.R.T. methodology to address the problems identified. The Goal shall be aligned with the customer CTQ Requirements. A clearly defines SCOPE is included in the PC. What is IN SCOPE and what is OUT OF SCOPE? Your Team is identified and Roles & Responsibilities are defined. A SIPOC Map is completed. An “As Is” Process Map is completed in order to better visualize the Work Flow in the current process. The DEFINE Phase provides for identification of the VOC and CTQs, their needs, Drivers and Requirements. The student will have evaluated and Affinitized the VOC. CTQ trees were created to identify key requirements for meeting the customer’s needs. The Project Team should have a list of external Key stake Holders, if applicable, e.g., Hospital Radiology, who may be impacted by process changes within the Doctor’s medical practice. If the Doctor’s staff schedule testing appointments for patients and are required to make frequent changes, this has an impact on the department or entity conducting the testing. The Project Team will have met with Dr. Deasley for his approval to proceed and now has a baseline to begin the Measure phase.

Measure 1. Based on Customer requirements the project team collected initial data. Use Pareto Analysis

of # occurrences data to determine the 5 factors which are causing over 95% of the problem with wait time. You need to determine the ‘biggest contributors to the problem. One tool to accomplish this is the Pareto Chart. You need to know if it is reasonable to assume that these five ‘parameters’ are normally distributed. (SEE APPENDIX B)

a. Based on Pareto Analysis what are the focus areas? b. Set up appropriate methods for tracking focus areas. You will need to track # of

occurrences of each category and actual for measuring the ability to meet the requirements.

2. Define your Data Collection Plan. Include the types of data you will be collecting (Discrete or Continuous), Why? (In many instances you will have a mix of both types of data depending on the Data source.

3. Based on the data collected Construct FIVE (5) histograms for the below data sets. (SEE APPENDIX C) for data sets

a. Interpret each of the histograms to determine whether the assumption of normality is reasonable.

b. If the data are not approximately normally distributed, why not? 4. The team also believed there was a Motorola shift during the process. Please describe the

Motorola Shift and potential causes that they could have experienced the shift. a. Calculate the PPM/DPMO for this process and determine the baseline sigma with

the Motorola shift. 5. Calculate the Process Performance, Pp and Ppk, based on the current process. Student will

be able to compare current Process performance to Capability Study performed for process improvements. Tint: drawing a picture of the data based on a Normal Curve may help student visualize if data is skewed when evaluating population distribution. Use UCL = 60 minutes and LCL = 0 Minutes. In Healthcare LCL will frequently be “O”

Conclusion of Measure: A Data Collection Plan was created. Data was taken of as many parameters as possible before changing any variables. Key Data has been provided for your use as directed in the instructions above. Pareto harts have been created and based on the VOC. The 5 Largest Contributing Factors will have been identified. These should have aligned with the data provided. A method for tracking data to capture for analysis should have been identified even if the actual data is already provided. Then from the categories and data

“collected”, 5 Histograms should have been created along with the narrative for Analysis, specifically related to determination if data was normally distributed. An explanation of the Motorola Shift is provided. PPM/DPMO is calculated. Pp/Ppk are calculated and current process Sigma Level is defined. It was found that Dr. Deasley was spending more time with his patients than necessary. The process needs to be analyzed based on the data.

Analyze 1. Create a Stem and Leaf Plot for the downtimes that were captured from the patient wait times

in the waiting rooms. (SEE APPENDIX D for data set) 2. Calculate Measures of central Tendency with Downtime data. What can you interpret from

these measures? Please document a conclusion (SEE APPENDIX D for data set) 3. Calculate Measures of Dispersion with Downtime data. What can you interpret from these

measures? Please document a conclusion (SEE APPENDIX D for data set) 4. Two individual staff members were being observed performing identical activities in the

Doctor’s office. 25 random samples were taken for each staff member. One of the Medical Assistants is a new employee. Medical Assistant #1 has been with Dr. Deasley for several years. Medical Assistant #2 is a new employee and has been with this medical practice for 9 months. We want to determine how Assistant 2 performs when compared to Medical Assistant #1. Since she is a new employee. (SEE APENDIX E for data sets)

5. Please provide the following information based on your analysis of the two Medical Assistants a. Medical Assistant #2 Average b. Medical Assistant #2 Standard Deviation c. Null Hypothesis d. Alternative Hypothesis e. T-Test Statistic f. Critical Value g. Statistical Conclusion for the null and alternative hypothesis.

Conclusion of Analyze: Stem and Leaf Plots were created from Downtime data provided, Measures of Central Tendency were also determined using Downtime data and an interpretation of the results were made. Data was analyzed to review if different staff members were performing similarly or not. Students should have established a Null Hypothesis and Alternative Hypothesis from the data for the 2 staff members. An appropriate test was performed and conclusions made based on the outcome.

IMPROVE 1. A staff member has been stating for months that there is a correlation between the Room

Availability and the Patient arrival time. Should the Office Manager have listened to this staff member’s observation? After completing items 2 through 5, provided your thoughts on staff observations and how they might have achieved Office Manager Buy-In sooner.

2. Construct a scatter diagram and calculate the correlation coefficient to see if she is correct. SEE APPENDIX F for data set

a. Is there strong correlation between room availability and patient arrival time? b. IF there is strong correlation, is it positive or negative? (Answer with positive, negative

or N/A) c. What is the correlation coefficient between the two variables? (Use 6 decimal places).

What does this mean? 3. Discuss the 8 Deadly Wastes (MUDA) of the process. 4. Create a Fishbone Diagram. List Potential Root Causes. Narrow Potential Root Causes to Key

Root Causes. Explaining some of the key Root causes. 5. Discuss Improvements that you would suggest based on findings from FISHBONE Analysis.

Conclusion of Improve: A Scatter Plot was constructed and a Correlation completed. The determination of whether the 2 factors Correlate based on a Correlation Coefficient determination is stated and comments on whether the correlation is Positive or Negative are included. 8 Wastes were evaluated and identified where applicable. A FISHBONE DIAGRAM was created and many ideas were brainstormed for Potential Root Cause. These were then narrowed to the critical few Root Causes. Many improvement suggestions were made.

CONTROL An I-MR chart was plotted for the Doctor’s office to ensure the specifications were performing as planned and the patients and Doctors were satisfied.

1. Please indicate if the control chart is stable and if any Shewhart Rules have occurred.

2. A normality test was conducted. Please advise if the data is normal.

3. A capability study was completed. Please advise if the process is stable and any analysis you

find is relevant.

4. Please complete a Control and Monitoring Plan for the project. 5. Create a Dashboard which the office can utilize to monitor the performance of the

improvements as well as supporting the sustainability of the improvements

Conclusion of Control: Conclusion regarding the stability of the Control Chart was made and any violations of the Shewhart Rules were noted. Students then observed the WET LAB TESTING and discussed the Normality of the data. A Capacity Study was done presumably using data from improvements made and analysis of the Mini Tab output was discussed. A Control and Monitoring Plan was created to ensure monitoring of improvements for Sustainability. Final a Dashboard was developed to be used for staff to visually track their performance and for discussion with Dr. Deasley. We have collected data after making many improvements to see if the process is now stable. We will continue to monitor our progress and follow the control plan.


 Please make final conclusions of the project.


Feedback from Patients:

I wait too long. I only have an hour for Lunch. I make my appointments specifically at Lunch time because I can’t come after work.

I like to come very early and be one of Dr. D’s first patients. If I am not his 1st, I end up waiting and am late for work. My company is very strict about being on time.

I wouldn’t mind if the doctor spent less time with me. I only usually come for an Annual Checkup and a Flu shot. If I feel really sick, I call the office. When I broke my arm last year, the doctor sent me right to the hospital. You guys made the arrangements for my X-Ray so I didn’t need to wait.

I can’t be late when I come in the afternoon. I need to pick my daughter up from school. If I come in the afternoon, can you make it a short visit?

The doctor spends so much time asking me questions, can’t he look at my chart before I get into the exam room?

The last time I was here, you put me in a room with someone else’s clothes. The woman had gone to the Ladies’ room and came back to get dressed. I had to wait in the hallway.

Feedback from Staff

We need to organize the exam rooms. Dr. Deasley is always looking for something and I need to go find it.

We can’t have multiple people at the Front desk assigning patients to rooms. They don’t always assign patients to the right room and equipment is not available

Dr. D keeps taking equipment with him from room to room,

The patients are not getting here early enough to get them ready for the doctor. He like to have their Blood Pressure, Weight and Temperature done before he comes in.

Patients keep arriving the last minute, then they get angry because they miss their appointment and need to wait.

I hope I never have to reschedule Mrs. Smyth for a new appointment because the doctor couldn’t see her. She was practically screaming at me.

We had 2 patients, Mrs. Jones and Mr. Thomas ask for their records to be sent to a new doctor’s office. That is the 4th time that has happened this year and we are only ½ way through the year.

The new Medical Assistant was complaining because she said there is too much chaos here. I think she might be sorry she came her. I hope she doesn’t go back to the hospital. It takes so much time to find good people and train them.

Feedback from Doctor

I don’t always have the instruments I need in the Exam Room. I need to have my Assistant go find what I need. I’ve started taking Instruments with me to my next patient only to find 3 of the same instrument I am carrying in the next Exam Room.

I have seen several patients waiting in the hall outside the Exam Room. I don’t like that situation. We need to stop this practice.

I see some staff running around like crazy and others sitting around appearing to have nothing to do.

I am not one of these “hands off’ doctors, I like to spend time with my patients. But sometimes a patient will sit there with nothing to say and another patient will have a long list of issues.

If this improvement project is successful, I would like to see 15 Patients a day. We need to keep operating costs in mind. We need to keep our equipment up to date and I need to ensure we plan for salaries and bonuses at year end.

I notice we have had 3 people leave within the past 18 months. I would like to understand why. It is very expensive to recruit staff and it takes time before they are proficient in their jobs. The team we have now is very good. I would like to keep all of them. We do monitor salaries and compare with market standards so I know our salaries and benefits are competitive.

Feedback from Other Sources

Radiology Department is complaining because they state we make too many changes to the patient appointments.

The Laboratory department is complaining because our patients are coming for testing outside their assigned appointment time and too late in the day.

APPENDIX B: Based on VOC data to be used to construct CTQ’s. Project Team will identify key focus areas in Doctor’s Office using Pareto Diagram. These focus areas will then be monitored as defined in Data Collection Plan.

Time the Doctor was spending with Patients – 79

Number of times Dr arrives late – 4

Proper Medical Devices not Available – 30

Number of times patient is left in the hallway – 17

Rooms Available at Doctor’s Office -22

Number of times staff arrive late – 3

Staffing of Doctor’s Office -41

Number of times scheduling changes were made for patient testing – 15

Number of times patient had to be rescheduled for Dr visit – 10

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