Quality Improvement Methods

Quality technique · See it on the map

Guide only — Choosing and applying an improvement method is a judgment call.

Formal, repeatable programs that drive down defects or variation across many measured cycles over time.

When to use it

A recurring quality problem important enough, and stable enough in its pattern, to be worth measuring, addressing in a structured cycle, and re-measuring — chronic rework, repeat defects across projects, or a process whose output varies more than the client will tolerate.

When to avoid it

A single project's one-off defect — fix it and move on, that's problem solving or root cause analysis, not a program. Also avoid standing up Six Sigma-level rigor (belts, control charts, statistical process control) for a problem a one-week fix would resolve; the program overhead will exceed the problem and it will not get finished.

Steps

1. Pick the method that fits the problem's scale: PDCA for a lightweight, fast repeat-and-adjust cycle; DMAIC (Define-Measure-Analyze-Improve-Control) for a problem worth statistical rigor; Lean for waste or non-value-add steps in a workflow.
2. Define the problem and measure a baseline before changing anything.
3. Plan a specific, small change targeting the suspected driver.
4. Run the change on a limited scope and measure the same metric again.
5. Compare against the baseline; if it improved, standardize the change; if not, revert and try the next candidate.
6. Repeat the cycle — these methods are iterative by design, not a single pass.
7. Once a change sticks, document the new standard so it doesn't quietly drift back to the old way.

What it produces

• A measured before/after comparison against a defined baseline.
• A standardized process change, or a documented and rejected candidate.
• A repeatable cycle set up to run again.

Common pitfalls

• Launching a full DMAIC-weight program for a problem a single fix would have resolved — the program itself becomes the overhead.
• Skipping the baseline measurement, so 'improvement' can't actually be shown.
• Treating one PDCA cycle as finished rather than as one loop in an ongoing process.

Worked example

Larch & Rowe sees drywall finish rework on roughly one in six jobs. Rather than a company-wide quality initiative, the ops lead runs a lightweight PDCA cycle: Plan — require a moisture check before mudding on the next ten jobs; Do — run it; Check — rework drops to one in fifteen; Act — make the moisture check standard practice on every job and retire the old sign-off sheet that didn't include it.

Source

• PMBOK-6 §8.2

Where it comes from: this technique is named by the PMBOK Guide, 6th edition.