{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Error - Control Chart Methods for Individual Measurements...

Info iconThis preview shows pages 1–10. Sign up to view the full content.

View Full Document Right Arrow Icon
Control Chart Methods for Individual Measurements IE 330: Lecture 9 2/11/2008
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Outline Why not sample more? Shewart type charts Example: White millbase dispersion process Exponentially weighted moving average control charts
Background image of page 2
Why not sample more? (n=1)
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
X and R m Control Charts Idea: Calculate the range from consecutive individual measurements: usually n=2 or 3 R A x ULC x CL R A x LCL 2 2 + = = - = X i = 12 15 13 12 14 18 13 R1=3 R2=3 R3=1 R4=6
Background image of page 4
n should be small: Special causes might be present Most misused: Only use if samples cannot be formed. 1. Higher variability 2. Large sampling errors X and R m Control Charts
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Construction of Control Charts Center line
Background image of page 6
Construction of Control Charts m m m R D R R D 4 3 UCL CL LCL = = =
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Construction of Control Charts ) ( ˆ 2 n d R m = σ m R R m d R mn x m x X m i i m i k j ij m i i x ∑∑ = = = = = = = = = 1 2 1 1 1 ; ) ( ˆ ; ˆ σ μ R A x k d R x k x x x 2 2 / 3 ˆ 3 ˆ 3 ˆ ± ± ± ± σ σ μ σ ˆ 3 ± X Estimate variance UCL and LCL
Background image of page 8
Example: White Millbase
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 10
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}