# Harnswell Sewing Machine Company

Topics: Process capability, Limit superior and limit inferior, Control chart Pages: 6 (1006 words) Published: January 24, 2011
Case Study

Harnswell Sewing Machine Company

IME 460 Case Study 2

Phase 1
Introduction

Harnswell Sewing Machine Company is dedicated to the manufacture of industrial sewing machines, has an experience of over 50 years in the market, this factory is specialized in the manufacture of automatic machines engaged in the manufacture of shoes, accessories and belts security.

Natalie York is the manager of operations management, currently on a master in business administration.

A few days ago Natalie was asked to find out how to improve quality in the process without much investment.

Phase 2

One day John proposed to Natalie a project on how to improve quality in the process production but by the end of the explanation, this made him leave his office, as is assumed Natalie was very depressed about what happened and that's where the supervisor Jim proposed plant will initiate an investigation and thus demonstrate to the owner of the company it was possible to increase the profitability of the company based on a quality improvement.

HS 7.3(a) Is this process in a state of statistical control? Why?

There are five observations for each day, the mean chart and the range chart will be use.

Overall:
= 0.507523
= .000183

Mean Chart:

| 0.507523|
UCL| 0.507628591|
LCL| 0.507417409|

Mention: the 17th point is below the lower control limit

Range Chart:
| 0.000183|
UCL| 0.000386928|
LCL| 0*|

* LCL=-0.000021 LCL=0

(b) What recommendations should be made about improving the process? We need to determine why the 17th point in mean chart out of the LCL.

Phase 3

After conducting research on the cam, Natalie analyze the graphs, which showed that on 17 last month had occurred outside the lower limit, which meant that production waste occurred.

Natalie realized reasons for such waste, which showed that the lot that morning was conducted in a very cold climate, which low productivity of employees. Jim had already spent months trying to persuade Mr Barnwell to install an automatic thermostat, but he always got rejected.

Thus, Natalie and Jim decided to take out of petty cash funds and other accounts to purchase the thermostat.

HS 7.4 What should Natalie now do concerning the data of the table? Explain Now the reason of waste occurs being eliminated, the problematic data could be removed from the table and then we got an improved control chart.

Overall:
= 0.507527
= .000179

Mean Chart:

| 0.507527|
UCL| 0.50763028|
LCL| 0.50742372|

Now that point outside the control limit.

Range Chart:

| 0.000179|
UCL| 0.00037847|
LCL| 0|

Also these are no point outside the control limit.

HS 7.5 Explain why the actions of Natalie and Jim to avoid this particular problem has resulted in improved quality in the future?

After the reason why the waste occurs eliminated, the probability of low diameter part being produced is reduced. Thus improve the production quality.

Phase 4

Having identified the reason of the problem of day 17, Natalie and Jim sat down with Dave Martin and several other operators to further identify all the causes for the existence of oversized and scrapped rollers.

HS 7.6 (a) Set up a frequency distribution or a stem-and-leaf display of the cam roller diameters presented in Table HS7.1. Explain why you chose the tabular presentation that you used?

Diameter| Frequency| Percent %| | |
0.5072| 1| 0.667| 62.667%| Within Limit|...