Performance and Process Improvement is the largest CPHQ category at 27 scored items. The content outline names three methods (Lean, PDSA and Six Sigma) and three tools (fishbone diagrams, FMEA and process maps). The exam rarely asks you to define them. It asks you to choose one.
The Model for Improvement and PDSA
The Model for Improvement, popularized by IHI, starts with three questions and then tests changes in rapid Plan-Do-Study-Act cycles.
What are we trying to accomplish?
A specific, time-bound aim: "Reduce ED door-to-provider time to under 30 minutes by June."
How will we know a change is an improvement?
Outcome, process and balancing measures tracked over time.
What change can we make that will result in improvement?
Ideas from evidence, other organizations and frontline staff, tested one at a time.
Tap each phase of the cycle to see what happens there.
State the objective and a prediction. Decide who, what, where and when, and what data you'll collect.
Exam pattern
When a scenario says "test," "pilot," "small scale" or "learn whether," PDSA is usually the answer. Multiple small cycles are better than one big one.
Lean: remove waste, improve flow
Lean, rooted in the Toyota Production System, defines value from the patient's perspective and removes everything else. Tools include value stream maps, 5S, standard work, visual management and kanban. The eight wastes are easy to recall as DOWNTIME. Tap each letter for a healthcare example.
Six Sigma: reduce variation and defects
Six Sigma uses statistics to make a process more consistent. At "six sigma" performance, a process produces about 3.4 defects per million opportunities. Projects follow DMAIC:
Define
Problem, scope, customer requirements and project charter.
Measure
Baseline performance and a reliable data collection plan.
Analyze
Find and verify root causes with data.
Improve
Develop, test and implement solutions.
Control
Sustain gains with monitoring, control charts and standard work.
Lean Six Sigma combines both: Lean for speed and flow, Six Sigma for precision.
Side-by-side comparison
| PDSA | Lean | Six Sigma | |
|---|---|---|---|
| Main goal | Test and learn quickly | Remove waste, improve flow | Reduce variation and defects |
| Structure | Plan, Do, Study, Act | Value, value stream, flow, pull, perfection | Define, Measure, Analyze, Improve, Control |
| Speed | Days to weeks per cycle | Days (rapid events) to months | Months |
| Data needs | Simple, often small samples | Time and flow observations | Heavy statistical analysis |
| Best for | Trying a new idea safely | Delays, bottlenecks, inefficiency | Complex, high-volume processes |
Practice with 500+ CPHQ questions
Scenario-based, mapped to the NAHQ content outline, with an explanation for every answer. Your first 50 are free.
Choose the right tool
This is exactly how the exam tests tools. Pick a goal to see the best match.
Pareto chart example
A surgical services team logged 100 first-case delays. The Pareto chart shows two causes drive 70% of the problem, so that's where to start.
Illustrative data.
Teams and leading change
The outline also covers establishing teams and leading change. Know these roles:
| Role | Responsibility |
|---|---|
| Executive sponsor | Removes barriers, secures resources and connects the work to strategy |
| Team leader | Manages the project, agenda and timeline |
| Facilitator | Guides process and tools, keeps discussion productive and neutral |
| Process owner | Accountable for the process and for sustaining the change |
| Frontline members | Know how the work is really done; essential for buy-in |
Expect questions on resistance to change. The best answers involve engaging the people affected early, communicating the "why" with data, and celebrating small wins.
Patients in an outpatient infusion center wait an average of 90 minutes from check-in to treatment. Much of the delay comes from walking between rooms, waiting for pharmacy and duplicate paperwork. Which method best fits?
The problems described (walking, waiting and duplicate paperwork) are classic Lean wastes: motion, waiting and extra processing. A value stream map shows each step and where time is lost. Six Sigma targets variation and defects, while RCA and FMEA focus on safety events and risks.
An improvement team has reduced catheter-associated urinary tract infections for three consecutive months. What should the team do to sustain the gain?
Sustainability is the "Control" (or "Act") stage: standardize the new process, assign ownership, and keep monitoring, often with a control chart, so backsliding is caught early. Disbanding or stopping measurement risks losing the improvement.
Frequently asked questions
PDSA is a rapid, small-scale test-of-change cycle. Six Sigma is a data-heavy project method (DMAIC) aimed at reducing variation and defects. PDSA is usually faster; Six Sigma suits complex, high-volume processes with measurable defects.
Yes. The content outline names Lean, PDSA and Six Sigma as performance improvement methods, and fishbone diagrams, FMEA and process maps as quality tools.
It organizes possible causes of a problem into categories. It does not rank causes; a Pareto chart does that.
Defects, overproduction, waiting, non-utilized talent, transportation, inventory, motion and extra processing, often remembered as DOWNTIME.
Figures are from NAHQ's 2024 CPHQ Detailed Content Outline (Revision 2b) and 2024 Domestic Candidate Handbook unless noted. Fees and policies change; the current handbook on nahq.org is the controlling source.