Quality Management: Focus on Lean-Six Sigma

Although most people would agree that ensuring quality in healthcare is of the utmost importance, many would disagree on exactly what “quality” means. From the customer’s perspective, Carvin (1987) defines eight dimensions of product quality:
1) Performance, 2) Features, 3) Reliability, 4) Conformance, 5) Durability, 6) Serviceability, 7) Esthetics and 8) Perceived Value. The healthcare industry is facing increasing pressure to not only increase quality but also to reduce costs.

Cost of Quality
The costs of quality or the costs of poor quality according to Juran and Godfrey (1998) are costs associated with providing a poor-quality product or service. The cost of quality is usually separated into four parts:

1. External Failure: costs associated with failure after the customer receives the product or service (e.g., bad publicity, liability, customer service)
2. Internal Failure: costs associated with failure before the customer receives the product or service (e.g., rework, replacement, correction of a problem)
3. Appraisal: costs associated with inspecting and evaluating the quality of supplies or final product/service (e.g., audits, accreditation preparation, and review)
4. Preventing: costs incurred to eliminate or minimize appraisal and failure costs (e.g., training, investment in systems)

Six Sigma
Six Sigma has been defined as a philosophy, methodology, set of tools, and goals. It is seen as a business strategy with a focus on eliminating defects through prevention and process improvement. Six Sigma is composed of a set of quantitative and qualitative statistically based tools used to provide management with facts to allow improvement of an organization’s performance. Six Sigma also represents a goal of no more than 3.4 defects per million opportunities (DPMO).

Six Sigma programs can take many forms, depending on the organization, but the successful ones all share some common themes:

 Top management support

 Extensive training at all levels of the organization

 Emphasis on Define, Measure, Analyze, Improve, and Control (DMAIC) approach

 Team-based projects for improvement

Define-Measure-Analyze-Improve-Control
DMAIC is the acronym for the five phases of a six-sigma project:

Define
In the definition phase, the six-sigma team chooses a project based on the strategic objectives of the business and the needs or requirements of the customers of the process.

Measure
In the measurement phase, the team determines the current capability and stability of the process.

Analyze
In the analysis phase, the team analyzes the data that have been collected to determine true root causes, or Key Process Input Variable (KPIV).

Improve
In the improvement phase, the team identifies, evaluates, and implements the improvement solution.

Control
In the control phase, controls are put in place to ensure that process improvement gains are maintained and the process does not revert to the old way.

Seven Basic Quality Tools
According to Kauro Ishikawa (1985), 95 percent of quality-related problems could be solved with these fundamental tools:

 Fishbone diagram: the tool for analyzing and illustrating the root causes of an effect.

 Checksheet: Simple form used to collect data

 Histogram: graph used to show frequency distributions

 Pareto chart: sorted histogram used to separate the vital few from the trivial many

 Flowchart: process map

 Scatter plot: the graphical technique to analyze the relationship between two variables

 Run chart: plot of a process characteristic used to examine trends

Lean Enterprise
The Healthcare industry is facing increasing pressure to employ resources in an effective manner to reduce costs and increase patient satisfaction. Recently many healthcare organizations have begun to realize the transformative potential of Lean (Panchak 2003; Womack et al. 2005).

What is Lean?
Lean has defined as philosophy, methodology, and set of tools. The Lean philosophy is to produce only what is needed when it is needed and with no waste. A Lean organization is focused on eliminating all types of waste. The Lean methodology begins by examining the system or process to determine where in the process value is added and where it is not; steps in the process that do not add value are eliminated, and those that do add value are optimized.

Types of Waste
Seven types of waste are found in organizations, and they can be reinterpreted for healthcare:

1. Overproduction
2. Waiting
3. Transportation
4. Inventory
5. Motion
6. Over-processing
7. Defect

Kaizen
Kaizen is viewed as both a general philosophy of improvement focusing on the entire system or value stream and a specific improvement technique focused on a particular process. The Kaizen philosophy of continuous improvement consists of five basic steps:

1. Specify value
2. Map and improve the value stream
3. Flow
4. Pull
5. Perfection

Value Stream Mapping
Value stream mapping is a type of process mapping or flow charting of the value stream, which includes all of the steps, both the value-adding and the non-adding value steps. Value stream mapping in healthcare is typically done from the perspective of the patient, where the goal is to optimize his journey through the system information. A common measurement for the progress of Lean initiatives is percent value added.
%Value added = Value-added time ÷Total time in system × 100

Takt Time
Takt time determines the speed with which customers must be served to satisfy a demand for the service.

Takt time = Available work time/Day ÷ Customer demand /Day

Cycle time is the actual time to accomplish a task in a system. Cycle time for a system will be equal to the longest task-cycle time in that system. In a Lean system, cycle time and take time are equal. If cycle time is greater than takt time, demand will not be satisfied and customers or patients will wait. If cycle time is less than takt, resources will be underutilized.

Throughput Time

Throughput time is the time for an item to complete the entire process. It includes waiting time and transport time as well as actual processing time. In a perfectly Lean system, there would be no waiting time and throughput time would be minimized.

Alliance Clinic

Alliance Clinic collected the data for a typical patient visit. Here, the physical exam and consultation have the longest task time, 20 minutes; therefore, the cycle time for this process is 20 minutes. Assuming that physician time is not constrained, every physician could output one patient from this process every 20 minutes. However, the throughput time is equal to the total amount of time a patient spends in the system. Here, it is:

3 + 15 + 2 + 15 + 5 + 10 + 20 = 70 minutes

The available work time per physician day is 5 hours (physician work 10 hours per day, but only 50 percent of that time is spent with patients), there are 8 physicians, and 100 patients are expected at the clinic every day.

Takt Time = 8 physicians × 5 hours/Day ÷ 100 patients/ Day = 0.4 physician hours/patient = 24 physician minutes/patient

Therefore, to meet the demand, the clinic needs to serve one patient every 24 minutes. Because cycle time is less than takt time, the clinic can meet demand. Assuming that patient check-in is necessary but non-value added and that both the nurse preliminary exam and the physical exam and consultation are value-added tasks, the value-added time for this process is: 5 Minutes (Nurse preliminary exam) + 20 Minutes (physician exam and consultation) = 25 Minutes and the present value-added time is: 25 Minutes/70 Minutes = 36%
A lean system works toward decreasing throughput time and increasing percent value-added time.

Five Ss
The five Ss are essentially ways to ensure a clean and organized workplace. The five practices typically used to describe them are:

1. Sort
2. Straighten
3. Sweep
4. Standardize
5. Sustain

Spaghetti Diagram
A spaghetti diagram is a visual representation of the movement or travel of material, employees, or customers. In healthcare, a spaghetti diagram is often used to document or investigate the movements of caregivers or patients. Typically, the patient or caregiver spends a significant amount of time moving from place to place and often backtracks. A spaghetti diagram can help to find and eliminate wasted movement in the system.

Standardized Work
Standardized work is written documentation of the precise way in which every step in a process should be performed. In the healthcare industry, examples of standardized work include treatment protocols and the establishment of a care path. (Care paths are examples of evidence-based medicine).