Articles

Practical techniques · Tool applications · Pitfall guides · Case studies · Data analysis · Improvement methods · Audit readiness

Concise, actionable knowledge for solving real problems at work

📄 28 articles in total 📅 Continuously updated 🔥 Pinned first, then sorted by rating, views and publish date
Six Sigma & Statistical Quality · Statistical Process Control · Process Capability Cpk / Ppk

Advancing QE Skills (12) | Cmk and Equipment Capability Acceptance: Quantitative Thresholds Before New Equipment Goes Online

1. Introduction: A "Qualified" Machine Fails After Three Months of Mass Production A manufacturing company recently purc…

Six Sigma & Statistical Quality · Statistical Process Control · Process Capability Cpk / Ppk

Advancing QE Skills (11) | Capability Analysis for Non-Normal Data: Transformation, Box-Cox, and Non-Parametric Methods

A mechanical processing company submitted an initial process capability report to a client, focusing on the roundness of…

Six Sigma & Statistical Quality · Statistical Process Control · Process Capability Cpk / Ppk

QE Skill Enhancement (10) | What's the Difference Between Cp/Cpk and Pp/Ppk: Correct Interpretation of Short-term and Long-term Capability

A precision machining company supplies drive shafts to a new energy client. During the client's audit, a process capabil…

Six Sigma & Statistical Quality · Statistical Process Control · Control Chart Selection & Out-of-Control Analysis

Control Limits Set Once and Never Changed? — A Five-Step Method for Establishing, Inspecting, and Updating Control Limits

During a process audit at an automotive parts company, an auditor pointed to the X̄–R control chart hanging on the wall …

Six Sigma & Statistical Quality · Statistical Process Control · Control Chart Selection & Out-of-Control Analysis

Tool Wear is Gradually Increasing, but the Control Chart Remains Silent? —— Five Steps for Monitoring Small Drifts with EWMA and CUSUM

An incident occurred at a machining company: during a quarterly inventory check, it was discovered that the scrap rate o…

Six Sigma & Statistical Quality · Statistical Process Control · Control Chart Selection & Out-of-Control Analysis

Can Control Charts Be Drawn for Only One Batch per Month per Variety? —— Five-Step Method for Selecting Three Types of Alternative Charts for Short-Cycle SPC

A quality engineer at a machining company has been staring at a control chart for two months, feeling frustrated. The ma…

Six Sigma & Statistical Quality · Statistical Process Control · Control Chart Selection & Out-of-Control Analysis

Subgrouping Mistakes Lead to False Signals on Control Charts — A Five-Step Method for Rational Subgrouping and Sampling Strategy

1. Daily Alarms, but No Issues Found on the Production Line A plastic injection molding company implemented an X̄ R cont…

Six Sigma & Statistical Quality · Statistical Process Control · Control Chart Selection & Out-of-Control Analysis

Control Charts Are Drawn Daily, Yet Fail to Catch Any Abnormalities? — A Case Study of Rebuilding the SPC "Alarm but No Response" Loop in an Electronic Connector Manufacturing Company

1. The Charts Are Drawn, the Points Are Plotted, but Soldering Defects Still Occur Two years ago, an electronic connecto…

Six Sigma & Statistical Quality · Statistical Process Control · Process Capability Cpk / Ppk

Cpk Only 0.82, Customer Issues an Ultimatum? — A Case Study of Process Capability Improvement in an Automotive Parts Company

1. Introduction: An Audit Report Reveals the True Picture An automotive parts company specializes in spline shafts, with…

Six Sigma & Statistical Quality · Statistical Process Control · Control Chart Selection & Out-of-Control Analysis

Practical Selection of Control Charts —— Choosing the Right Chart Ensures Half the Success in Process Monitoring

Abstract : The inability to create a control chart is a capability issue, but choosing the wrong chart is a directional …

Six Sigma & Statistical Quality · Statistical Process Control · SPC Digital Practices

Five-Step Method for Digital SPC Implementation — Making Control Charts Truly Run on the Production Line

1. Why Digital SPC Often Fails to Deliver Many companies have implemented SPC software and purchased monitoring screens,…

Six Sigma & Statistical Quality · Statistical Process Control · Process Capability Cpk / Ppk

Detailed Steps for Calculating Cpk — A Practical Guide from Data Collection to Capability Assessment

1. What Does Cpk Address? The process capability index Cpk Process Capability Index is one of the most commonly used sta…