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Process Improvement through SPC

Norman Greig

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Process understanding and improvement through SPC
An introduction to SPC tools and techniques and how they can be used to understand and improve processes (and increase profits) Norman Greig CCS Associates Limited Tectona House Dunmow, Essex, CM6 2AT, UK Tel/fax +44 (0)1371 859200 Contact: Norman Greig info@ccsassociates.com www.ccsassociates.com

Process understanding and improvement through SPC
SPC concepts and key tools SPC as a basis for quality control & process control Types and causes of variability and which ones to tackle first Selecting and understanding control charts for variables and attributes Types of control charts and how to interpret them How to set limits and targets for control charts Introduction to Pareto Analysis- sorting the vital few from the trivial many Process Capability - what is it and how to measure it FMEA: Key steps in Process Failure Mode and Effects Analysis The next steps in implementing SPC

SPC & PROCESS IMPROVEMENT

© 2006-2010 CCS Associates Ltd. Norman Greig

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SPC & PROCESS IMPROVEMENT

© 2006-2010 CCS Associates Ltd. Norman Greig

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What are Today’s challenges in manufacturing?
• Getting information about a process NO • How to get more value from all the data that is already being collected. • Understanding the process and getting the right information to the right people at the right time SPC & PROCESS IMPROVEMENT © 2006-2010 CCS Associates Ltd. Norman Greig 3

Statistical Process Control
Process Analytical Techniques

SPC & PROCESS IMPROVEMENT

© 2006-2010 CCS Associates Ltd. Norman Greig

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Traditional QC v SPC
Statistical Process Control Action on the PROCESS Traditional Quality Control Action on Information the product about performance Information about the product

Why Statistics?

people

equipment

materials

The Process
methods environment
© 2006-2010 CCS Associates Ltd. Norman Greig

The Product

Allows conformity to be judged objectively

Allows sensible sampling plans to be designed

Predictions can be made with known precision and risk

More economical

SPC & PROCESS IMPROVEMENT

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SPC & PROCESS IMPROVEMENT

© 2006-2010 CCS Associates Ltd. Norman Greig

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CCS Associates Limited SPC & Process Improvement Consultants Tectona House, Great Dunmow, Essex , CM6 2AT tel./fax: 0044 (0) 1371 859 200 www.ccsassociates.com ngreig@ccsassociates.com

Process Improvement through SPC

Norman Greig

2

What is Statistical Process Control?
Variability is inherent in every manufacturing process, which causes product to vary – even if only slightly

Sources of variation – causes

Statistical Process Control is the application of simple statistical methods to measure and control this variability during manufacture SPC & PROCESS IMPROVEMENT © 2006-2010 CCS Associates Ltd. Norman Greig 8 SPC & PROCESS IMPROVEMENT © 2006-2010 CCS Associates Ltd. Norman Greig 9

Types of Variation in the Process
PERFECT CONSISTENCY IN A PROCESS IS NOT ATTAINABLE TO MANAGE A PROCESS WITHIN AN ACCEPTABLE VARIATION THE CAUSE OF THE VARIATION MUST BE DETERMINED AND QUANTIFIED

Stages of Process Improvement

Piecing together the SPC puzzle Types of causes of variation: Common Causes: (Random Variation)
Many small sources Stable & relatively predictable Permanent unless action taken.

Assignable Causes (Special Disturbances)
One of few major causes. May be irregular May reappear unless action taken

SPC & PROCESS IMPROVEMENT

© 2006-2010 CCS Associates Ltd. Norman Greig

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SPC & PROCESS IMPROVEMENT

© 2006-2010 CCS Associates Ltd. Norman Greig

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Example SPC techniques & tools
55 12 55 10
Tally chart
x x x

Control charts for measurement variables
• Setting values for centre line, upper and lower limits. • The differences between control limits and specification limits • Interpreting charts - when to act - when to leave well alone • Finding...
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