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Johns Hopkins Nursing

Center for Nursing Inquiry

"Quality is everyone's responsibility" - W. Edwards Deming

Quality Improvement

What is Quality Improvement?

Quality Improvement (QI) is a structured, systematic approach to improving how care is delivered by testing changes in real practice settings and measuring their impact over time. 

QI focuses on:

  • Improving processes and outcomes
  • Using data to guide decisions 
  • Making small, rapid tests of change 
  • Embedding successful changes into daily work 

In healthcare, QI supports care that is safe, timely, effective, efficient, equitable, and patient-centered.

  1. 1939 (Milestone): PDSA Cycle Developed

    The plan-do-study-act (PDSA) cycle was developed by Walter Shewhart and W. Edwards Deming, engineers at Bell Labs (now known as Nokia Bell Labs) 4, 12. The cycle is also sometimes referred to as the Shewhart Cycle or the Deming Wheel. Shewhart and Deming used the steps of the scientific method as the foundation for the cycle 4, 12. Each step of the scientific method correlates to a step in the PDSA cycle: make a hypothesis is plan, test the hypothesis is do, examine the results is study, and report the results is act. The cycle is a never ending process, continually working to improve quality. The PDSA cycle is a precursor to the Model for Improvement.

  2. 1948 (Milestone): Toyota Production System Developed

    The Toyota Production System (TPS) was developed by Taiichi Ohno and Eiji Toyoda, engineers at Toyota Motor Company 3, 9, 14, 16. After World War II, Japan experienced critical supply shortages that prevented companies from producing large batches of inventory . The TPS streamlined the production process to eliminate any process that did not add value to the product, including overproduction and excess inventory 3, 9, 14, 16. The TPS is a precursor to Lean.

  3. 1986 (Milestone): Six Sigma Developed

    The Six Sigma model was developed by Bill Smith, an engineer at Motorola, after the company received too many warranty claims 3, 11. The Six Sigma model standardized the manufacturing process to eliminate defects. Today, Six Sigma principles are widely adopted among Fortune 500 companies, such as General Electric, Verizon, and IBM 3, 11.

  4. 1988 (Milestone): The Term Lean Coined

    The term "lean production" was first used in the article, Triumph of the Lean Production System, by John Krafcik 9. He used the term to describe the TPS.

  5. 1990 (Milestone): Lean Gained Popularity

    The Machine that Changed the World by Womack et al. was published in 1990 16. It detailed the Massachusetts Institute of Technology's five year study of the car manufacturing industry . The study found Lean principles enabled Toyota to overtake the top car manufacturers of the time, such as Ford and General Motors 3, 14, 16. Because of this, Lean gained popularity and expanded to industries outside car manufacturing.

  6. 1996 (Milestone): Model for Improvement Developed

    The Associates for Process Improvement, an Institute for Healthcare Improvement (IHI) partner organization, expanded on the PDSA cycle to create the Model for Improvement 10. It is now the most commonly used QI approach in healthcare 1.

QI at a Glance

QI is. . .

  • Improving how care is delivered
  • Testing change in practice
  • Using data and evidence to learn
  • Focused on a specific setting

QI is not. . .

  • Generalizable research
  • Controlled trials
  • Defining best practice
  • One-time implementation

The Improvement Process

Quality improvement follows a common process across models and settings. 

  1. Define the opportunity for improvement 
  2. Assess current performance 
  3. Identify why the problem is occurring 
  4. Design and test an improvement approach 
  5. Evaluate the results 
  6. Refine, sustain, or expand the change 

Models and Frameworks 

Quality improvement work is guided by structured models that support planning, testing, and evaluating changes in practice. Different models emphasize different aspects of improvement, and the choice of approach depends on the nature of the problem being addressed.

Common Quality Improvement Models in Healthcare

  • Model for Improvement focuses on testing changes and learning quickly through iterative cycles. 
  • Lean focuses on improving efficiency by identifying and reducing waste. 
  • Six Sigma focuses on reducing errors and variation in processes. 

 

Model Primary Focus Best Used When. . . 
 Model for Improvement  Testing changes and learning quickly  You want to improve a process using small, rapid tests of change 
 Lean  Eliminating waste and improving flow The process feels inefficient, redundant, or delayed 
 Six Sigma  Reducing defects and variation  Errors or inconsistencies are the main problem 

 

Choosing the Right Improvement Approach

Testing and refining a change?  >>> Model for Improvement

Inefficiency or waste?  >>>  Lean

Errors or variation?  >>> 

Quality Improvement Tools

QI work is supported by a range of practical tools used to define aims, understand processes, test changes, and evaluate impact. Not every project requires every tool. 

Category Explanation Example: Tools
 Cause Analysis  Tools that help uncover the 'why' behind a problem by identifying root causes.   Root Cause Analysis, 5 Whys, Fishbone Diagram   
 Evaluation & Decision-Making Tools that help prioritize, compare, or decide where to focus improvement efforts. Pareto Chart, Scatter Plot, Impact/Effort Matrix
 Process Analysis Tools that map and assess processes to reveal gaps, waste, or risks. Flowchart, Value Stream Mapping, FMEA
 Data Collection & Analysis Tools that track and interpret data to monitor performance and variation. Run Chart, Control Chart, Histogram, Checklist
Idea Creation Tools that generate, organize, and test new improvement ideas. Brainstorming, Affinity Diagram, Kaizen Event, 5S
Project Planning & Implementation Tools that define goals, set direction, and manage improvement work. SMART Aims, Stakeholder Analysis, A3 Report, Gantt Chart
Knowledge Transfer & Spread Tools that share results and sustain improvements over time. Storyboard, Standard Work, Kamishibai Board, Audit

What to Do Next 

Choose the step that best fits where you are right now: 

Need ideas or examples? 
>>> Review common QI tools and examples 

Have a problem but not sure how to approach it? 
>>> Schedule a consultation to clarify next steps 

Want to build QI skills or confidence? 
>>> Attend a QI-focused workshop or series.

Ready to launch or expand a project? 
>>> Get feedback before moving forward

 

Learn More

Agency for Healthcare Research and Quality – Practical QI tools and guidance 

Institute for Healthcare Improvement – Patient Safety Essentials Toolkit 

Armstrong Institute for Patient Safety and Quality – Training and system-level improvement initiatives