Skip to Content
Industrial Statistics with Minitab
book

Industrial Statistics with Minitab

by Pere Grima Cintas, Lluis Marco Almagro, Xavier Tort-Martorell Llabres
October 2012
Beginner
420 pages
9h 37m
English
Wiley
Content preview from Industrial Statistics with Minitab

21.2 Mattresses (1st Part)

A manufacturing process of springs for mattresses produces 3000 of such type of springs per hour, working continuously from 7 a.m to 10 p.m. As part of a Six Sigma improvement project, the decision is taken to implement a statistical control of this process. For this, every three hours a sample of 4 springs is taken and their length is measured by applying a force of 1 kg. According to the specifications, under these conditions, the length should be between 13.5 and 14.5 cm.
The data corresponding to the first week are in columns named Length 1, Time 1, and Day 1 of file MATTRESSES.MTW (the other three columns will be used in the second part of this case).
We are interested in which conclusions can be drawn from the - R control chart constructed using the data of the first week, and whether we deal with a capable process.

To draw the - R chart, do the following.

Stat > Control Charts > Variables Charts for Subgroups > Xbar–R

nc21uf008.eps

In the graphs obtained, two special causes are clearly identified. One is periodic: every day at 7 a.m., the springs are too long (they are only slightly compressed). The other cause is linked to an increase of the variability ...

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.

Read now

Unlock full access

More than 5,000 organizations count on O’Reilly

AirBnbBlueOriginElectronic ArtsHomeDepotNasdaqRakutenTata Consultancy Services

QuotationMarkO’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.
Julian F.
Head of Cybersecurity
QuotationMarkI wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.
Addison B.
Field Engineer
QuotationMarkI’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.
Amir M.
Data Platform Tech Lead
QuotationMarkI'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Mark W.
Embedded Software Engineer

You might also like

Statistics for Six Sigma Green Belts with Minitab and JMP

Statistics for Six Sigma Green Belts with Minitab and JMP

David M. Levine
Reliability Prediction and Testing Textbook

Reliability Prediction and Testing Textbook

Lev M. Klyatis, Edward L. Anderson
Minitab Cookbook

Minitab Cookbook

Isaac A Newton

Publisher Resources

ISBN: 9781118383780Purchase book