Manufacturing QA and continuous improvement · Lesson 3 of 4

Manufacturing QA and continuous improvement: methods and worked application

Root cause analysis in seven steps, five whys with its validation question, a worked FMEA on a painted coping order, the stronger-to-weaker ranking of corrective actions, and the lean tools that keep an improvement in place.

You will be able to: Run a root cause analysis and a simple FMEA on a flashing job, record the assumptions and ratings, rank corrective actions by strength, and choose the tools that hold the gain.

11 min · 11 slides · 8 questions

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Slide 1 of 11

Root cause analysis in seven steps

The U.S. Centers for Medicare & Medicaid Services (CMS) describes root cause analysis (RCA) as a structured, facilitated team process to find root causes and develop corrective actions.

Seven steps: identify the event and gather facts; charter a team; describe what happened; find contributing factors; find root causes; design and implement changes; measure their success.

1: Identify the event and gather information (photographs, documents, interviews, quarantined items)
2: Charter the team and a facilitator
3: Describe what happened
4: Identify the contributing factors
5: Identify the root causes
6: Design and implement changes to remove the root causes
7: Measure the success of the changes

The steps from the U.S. Centers for Medicare & Medicaid Services root cause analysis guidance, applied here to a shop.

Sources

Guidance for Performing Root Cause Analysis (RCA) with Performance Improvement Projects (PIPs), QAPI tool - U.S. Centers for Medicare & Medicaid Services

Videos for this lesson

What this video shows: Toyota explains poka-yoke: devices in the process that prevent, correct or highlight errors, such as a jig that only holds parts the right way. Checked against the video's description.

Video: The Toyota Production System as Taught by Toyota - Episode 02 by Toyota Motor Corporation, on YouTube. AFS checked its description against this lesson.

What this video shows: A clip from a HarvardX improvement-science course (written for health care) on drawing a cause-and-effect, or fishbone, diagram to lay out the possible causes of an effect. Checked against the video's description.

Video: How to create cause-and-effect diagrams by Harvard Online, on YouTube. AFS checked its description against this lesson.

Glossary

Root cause: An underlying process or system issue that led to an event. In the CMS five-whys test, an answer is a root cause only if correcting it would stop the problem recurring; otherwise it is a contributing factor.
Contributing factor: A situation or condition that made an event more likely but is not its root cause: if it were corrected, the problem would probably still recur (CMS five-whys test).
Failure mode and effects analysis (FMEA): CMS: a structured way to identify potential failures and their effects before an adverse event, rating each failure's severity and probability to choose what to fix first.
Forcing function: CMS: an engineering control that forces the user to complete an action, ranked among the stronger corrective actions because it does not allow the error.
Standard work: EPA: the documented sequence of activities for an operation, the baseline for measuring progress; it ensures consistency and prevents errors.