Accendo Reliability

Your Reliability Engineering Professional Development Site

Home » Articles » on Tools & Techniques » Page 41

on Tools & Techniques

A listing in reverse chronological order of articles by:


by 2 Comments

Process Capability Analysis II – Percent Defective Estimates

Process Capability Analysis II – Percent Defective Estimates

Introduction

In my prior article, Process Capability I – Overview and Indices, the process capability concept was defined for prototype samples and serial production. The data is assumed to be normally distributed and Pp, Ppk, Cp, and Cpk indices were defined. Its application to one-sided and two-sided tolerances was discussed. This article provides methods to estimate the percent defective.

The Data

The engineering tolerance for a critical characteristic is 10±0.2. So the lower specification limit (LSL) is 9.8 and the upper specification limit (USL) is 10.2. A sample of 30 parts provided measurements of the critical characteristic. The sample mean ($-\bar{x}-$) was 9.951 and the sample standard deviation (s) was 0.1825.

[Read more…]

by 4 Comments

Process Capability Analysis I – Overview and Indices

Process Capability Analysis I – Overview and Indices

Introduction

How is a manufacturing process determined to be capable of producing parts that meet engineering requirements? Some, like the finish of a gear tooth are critical, while the roughness of a non-contact surface isn’t critical. The critical characteristics need to be identified and checked to determine if the process is capable.

This article defines the analysis concepts and indices.

Prototypes and Series Production

Process capability assessments (PCA) start during the product development process and continue into series production. Prototype parts are created by a variety of methods, ranging from hand-crafted parts to short term manufacturing in a production intent process under factory conditions. The methods that are closest to series production are the most realistic.

[Read more…]

by Leave a Comment

Manufacturing Projects

Manufacturing Projects

How do I know your projects are valuable?

We have resolved many manufacturing issues. Why do I need DOE to do this? How can we better get to root cause? Each section below contains a 2-minute video to expand on the topic provided.

Why use Design Of Experiments?

Design of Experiments is the best tool for resolving problems when our science and experience fails us. Even if we are right, we also need to prove our approach works to others. Today that includes proof with statistical confidence. We need to be efficient to reduce excessive prototypes, scrap and downtime.

[Read more…]

by Leave a Comment

Achieving Innovation

Achieving Innovation

We want to be more innovative – but how?

Many companies talk about their desire for Innovation. Can Design of Experiments (DOE) help in that process? Each section below contains a 2-minute video to expand on the topic provided.

Too often, we manage on hope

How often do we hear a design or process development team express optimism – “We are almost there!” And how long does that same response continue without progress? The key is to decide when we have tried long enough using informal methods. Predictability and confidence are important to achieve project success.

[Read more…]

by Leave a Comment

Note from “Inside FMEA” Author

As of the date of this note, the Inside FMEA series of articles has completed the “Introduction to FMEA Series,” and is nearly complete with the “FMEA Fundamentals Series.”

This year, Inside FMEA articles will continue on a monthly basis. Each article will be posted for readers on the 1st day of the month.

As soon as the “FMEA Fundamentals Series” is completed, articles will continue with the “FMEA Preparation Series,” followed by the “FMEA Facilitation Series” and the “FMEA Special Topics Series.”

Readers of my book, Effective FMEAs, will continue to find the content of the Inside FMEA articles consistent with the concepts in the book.

It is my sincere desire that each and every person who reads Inside FMEA articles will discover the articles enjoyable to read and experience improved success in FMEA applications. As I say to readers of my book, “best wishes for effective FMEAs.”

Carl S. Carlson

 

by Leave a Comment

Telematics Data – Contour Plots and Multiple Parameter Analysis

Telematics Data – Contour Plots and Multiple Parameter Analysis

Introduction

The analysis of telematics data with two or more parameters is a complex process. The analysis of multiple parameters using contour plots is a powerful tool since a lot of information is captured in the graphics.

The best results come from a team effort. For engineering data, the team may consist of the design/development engineers, a programmer, and a reliability engineer or a statistician. The following is an analysis of engine speed, engine torque, and the transmission gear state to describe the process.

[Read more…]