Table 1 Run length profile of Bayesian Max-EWMA control chart as a result of a shift in Weibull parameters W(1, 1.5) with \(\gamma\) = 0.10 and considering subgroup size as 3, 5, and 7.
From: Memory type Max-EWMA control chart for the Weibull process under the Bayesian theory
\(\alpha\) | n | Shape parameter = \(\lambda\) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0.50 | 1.00 | 1.25 | 1.50 | 1.75 | 2.00 | 2.25 | 2.50 | 2.75 | 3.00 | 4.00 | 5.00 | ||
ARL (SDRL) | ARL (SDRL) | ARL (SDRL) | ARL (SDRL) | ARL (SDRL) | ARL (SDRL) | ARL (SDRL) | ARL (SDRL) | ARL (SDRL) | ARL (SDRL) | ARL (SDRL) | ARL (SDRL) | ||
0.25 | (µ,σ) | (−1.51,2.04) | (−1.49,0.89) | (−1.45,0.72) | (−1.42,0.61) | (−1.40,0.53) | (−1.38,0.47) | (−1.36,0.42) | (−1.35,0.38) | (−1.33,0.35) | (−1.32,0.32) | (−1.29,0.25) | (−1.28,0.20) |
3 | 3.25 (1.23) | 3.47 (0.76) | 3.53 (0.65) | 3.59 (0.60) | 3.63 (0.56) | 3.69 (0.53) | 3.75 (0.51) | 3.79 (0.46) | 3.84 (0.43) | 3.90 (0.36) | 3.96 (0.30) | 3.95 (0.22) | |
5 | 2.52 (0.81) | 2.69 (0.56) | 2.77 (0.49) | 2.84 (0.42) | 2.90 (0.35) | 2.93 (0.30) | 2.97 (0.22) | 2.98 (0.17) | 3.00 (0.12) | 3.00 (0.09) | 2.99 (0.09) | 2.96 (0.18) | |
7 | 2.18 (0.62) | 2.27 (0.45) | 2.29 (0.45) | 2.32 (0.47) | 2.35 (0.47) | 2.39 (0.48) | 2.45 (0.49) | 2.49 (0.49) | 2.56 (0.49) | 2.60 (0.48) | 2.67 (0.46) | 2.45 (0.49) | |
0.50 | (µ,σ) | (−0.68,3.16) | (−0.87,1.11) | (−0.84,0.90) | (−0.81,0.76) | (−0.78,0.66) | (−0.76,0.58) | (−0.74,0.53) | (−0,72,0.48) | (−0.71,0.44) | (−0.70,0.40) | (−0.66,0.31) | (−0.64,0.25) |
3 | 2.67 (1.15) | 6.38 (2.38) | 6.61 (2.12) | 6.94 (1.98) | 7.22 (1.83) | 7.33 (1.64) | 7.47 (1.59) | 7.49 (1.48) | 7.33 (1.40) | 7.05 (1.34) | 5.97 (1.17) | 5.16 (0.90) | |
5 | 1.32 (0.46) | 4.78 (1.53) | 4.89 (1.31) | 5.07 (1.19) | 5.24 (1.09) | 5.30 (0.98) | 5.33 (0.91) | 5.20 (0.86) | 4.96 (0.80) | 4.67 (0.78) | 3.87 (0.60) | 3.38 (0.51) | |
7 | 1.63 (0.57) | 3.95 (1.13) | 4.06 (0.98) | 4.20 (0.89) | 4.33 (0.81) | 4.35 (0.71) | 4.35 (0.67) | 4.21 (0.64) | 4.00 (0.63) | 3.71 (0.59) | 3.09 (0.40) | 2.83 (0.38) | |
0.75 | (µ,σ) | (0.01,4.18) | (−0.42,1.30) | (−0.39,1.05) | (−0.36, 0.88) | (−0.34,0.77) | (−0.32, 0.68) | (−0.29, 0.61) | (−0.28,0.56) | (−0.26,0.51) | (−0.25,0.47) | (−0.21,0.37) | (−0.18,0.30) |
3 | 1.98 (0.88) | 13.17 (7.45) | 19.84 (12.19) | 24.29 (14.79) | 25.45 (14.48) | 21.41 (10.90) | 17.09 (7.96) | 13.76 (5.55) | 11.31 (4.07) | 9.76 (3.08) | 7.10 | 5.87 (1.18) | |
5 | 1.49 (0.57) | 9.38 (4.40) | 13.36 (6.90) | 15.53 (7.53) | 14.69 (6.15) | 11.76 (4.33) | 9.18 (2.93) | 7.63 (2.16) | 6.46 (1.62) | 5.73 (1.28) | 4.44 (0.79) | 3.79 (0.60) | |
1.24 (0.43) | 7.50 (3.16) | 10.48 (4.85) | 11.79 (5.05) | 11.03 (3.91) | 8.75 (2.63) | 6.81 (1.85) | 5.74 (1.37) | 4.95 (1.02) | 4.45 (0.86) | 3.51 (0.57) | 3.05 (0.37) | ||
1.0 | (µ,σ) | (0.61,5.00) | (−0.05,1.47) | (−0.03,1.18) | (0.00, 1.00) | (0.03,0.87) | (0.05,0.77) | (0.07,0.69) | (0.09,0.63) | (0.11,0.58) | (0.12,0.54) | (0.16,0.41) | (0.19,0.34) |
3 | 1.64 (0.72) | 13.49 (8.07) | 54.86 (45.68) | 370.93 (366.30) | 175.64 (164.11) | 56.06 (43.89) | 25.21 (14.91) | 19.93 (10.69) | 15.17 (6.67) | 12.85 (5.03) | 8.04 (2.16) | 6.55 (1.44) | |
5 | 1.26 (0.47) | 8.48 (4.10) | 31.98 (24.00) | 369.15 (363.70) | 80.19 (69.05) | 24.05 (14.24) | 13.71 (5.98) | 10.14 (3.62) | 8.16 (2.47) | 7.12 (1.95) | 4.88 (0.95) | 4.13 (0.69) | |
10 | 1.10 (0.31) | 6.53 (2.80) | 23.33 (15.76) | 370.78 (366.11) | 49.18 (38.50) | 16.04 (7.92) | 9.72 (3.51) | 7.43 (2.19) | 6.17 (1.55) | 5.39 (1.23) | 3.84 (0.65) | 3.28 (0.50) | |
1.25 | (µ,σ) | (1.17,5.69) | (0.28,1.65) | (0.29,1.31) | (0.32,1.11) | (0.35,0.96) | (0.37,0.86) | (0.39,0.77) | (0.41,0.70) | (0.43, 0.64) | (0.45,0.60) | (0.49,0.46) | (0.52,0.38) |
3 | 1.46 (0.63) | 8.55 (4.46) | 17.12 (10.76) | 24.91 (17.03) | 25.22 (16.24) | 23.21 (13.62) | 20.39 (10.21) | 17.54 (7.84) | 14.97 (5.75) | 13.28 (4.62) | 9.10 (2.49) | 7.32 (1.74) | |
5 | 1.17 (0.38) | 5.69 (2.38) | 11.35 (5.94) | 16.92 (9.87) | 16.24 (8.73) | 14.70 (6.86) | 12.65 (4.90) | 10.64 (3.45) | 9.08 (2.58) | 8.11 (2.14) | 6.03 (1.38) | 6.63 (1.65) | |
10 | 1.05 (0.23) | 4.49 (1.66) | 8.81 (4.02) | 13.14 (6.87) | 12.38 (5.88) | 11.23 (4.47) | 9.62 (3.14) | 8.18 (2.26) | 6.98 (1.70) | 6.26 (1.43) | 4.32 (0.81) | 3.59 (0.59) | |
v\(\alpha\) | N | Shape parameter = \(\lambda\) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0.50 | 1.00 | 1.25 | 1.50 | 1.75 | 2.00 | 2.25 | 2.50 | 2.75 | 3.00 | 4.00 | 5.00 | ||
ARL (SDRL) | ARL (SDRL) | ARL (SDRL) | ARL (SDRL) | ARL (SDRL) | ARL (SDRL) | ARL (SDRL) | ARL (SDRL) | ARL (SDRL) | ARL (SDRL) | ARL (SDRL) | ARL (SDRL) | ||
1.50 | (µ, σ) | (1.67, 6.26) | (0.58, 1.86) | (0.58, 1.44) | (0.61, 1.21) | (0.64, 1.05) | (0.66, 0.94) | (0.68, 0.84) | (0.70, 0.77) | (0.72, 0.71) | (0.74, 0.65) | (0.79, 0.51) | (0.82, 0.41) |
3 | 1.35 (0.56) | 5.69 (2.63) | 8.64 (4.27) | 9.82 (4.76) | 9.54 (4.21) | 9.15 (3.65) | 8.82 (3.07) | 8.41 ( 2.68) | 8.13 (2.39) | 7.73 (1.99) | 6.89 (1.33) | 6.35 (1.00) | |
5 | 1.10 ( 0.31) | 4.00 ( 1.49) | 6.23 ( 2.54) | 7.06 ( 2.89) | 6.80 ( 2.50) | 6.55 ( 2.13) | 6.29 ( 1.81) | 6.04 ( 1.57) | 5.76 ( 1.35) | 5.57 ( 1.17) | 4.97 ( 0.78) | 12.32 ( 5.02) | |
7 | 1.02 ( 0.16) | 3.31 ( 1.12) | 5.09 ( 1.86) | 5.80 ( 2.16) | 5.58 ( 1.86) | 3.02 ( 0.99) | 5.11 ( 1.31) | 4.96 ( 1.16) | 4.77 ( 0.99) | 4.40 ( 0.69) | 4.08 ( 0.59) | 3.67 ( 0.52) | |
2.00 | (µ, σ) | (2.57, 7.16) | (1.16, 2.43) | (1.11, 1.70) | (1.13, 1.41) | (1.15, 1.23) | (1.18, 1.09) | (1.20, 0.98) | (1.23, 0.89) | (1.25, 0.82) | (1.26, 0.76) | (1.32, 0.59) | (1.36, 0.48) |
3 | 1.24 (0.46) | 3.53 (1.47) | 4.47 (1.81) | 4.70 (1.76) | 4.64 (1.58) | 4.49 (1.37) | 4.40 (1.21) | 4.26 (1.04) | 4.16 (0.94) | 4.13 (0.86) | 3.87 (0.64) | 3.75 (0.54) | |
5 | 1.05 ( 0.23) | 2.44 ( 0.82) | 3.41 ( 1.15) | 3.60 ( 1.17) | 3.52 ( 1.01) | 2.26 ( 0.47) | 3.34 ( 0.78) | 3.26 ( 0.69) | 3.19 ( 0.62) | 3.16 ( 0.56) | 3.02 ( 0.40) | 2.96 ( 0.29) | |
7 | 1.01 ( 0.11) | 2.07 ( 0.63) | 2.89 ( 0.89) | 3.02 ( 0.88) | 2.97 ( 0.79) | 2.89 ( 0.69) | 2.83 ( 0.62) | 2.77 ( 0.57) | 2.71 ( 0.54) | 2.68 ( 0.52) | 2.57 ( 0.49) | 2.46 ( 0.49) | |
2.50 | (µ, σ) | (3.33, 7.82) | (1.74, 3.18) | (1.59, 2.05) | (1.59, 1.61) | (1.62, 1.39) | (1.64, 1.23) | (1.67, 1.11) | (1.69, 1.01) | (1.72, 0.93) | (1.73, 0.86) | (1.80, 0.67) | (1.84, 0.55) |
3 | 1.18 (0.41) | 2.26 (0.94) | 3.14 (1.18) | 3.31 (1.13) | 3.25 (1.00) | 3.18 (0.89) | 3.11 (0.77) | 3.06 (0.71) | 3.01 (0.64) | 2.99 (0.60) | 2.88 (0.46) | 2.82 (0.46) | |
5 | 1.03 ( 0.18) | 1.74 ( 0.63) | 2.45 ( 0.78) | 2.60 ( 0.77) | 2.55 ( 0.68) | 2.49 ( 0.60) | 2.43 ( 0.55) | 2.40 ( 0.52) | 2.33 ( 0.49) | 2.31 ( 0.46) | 2.16 ( 0.37) | 2.08 ( 0.27) | |
7 | 1.00 ( 0.07) | 1.49 ( 0.54) | 2.10 ( 0.62) | 2.25 ( 0.59) | 2.22 ( 0.52) | 2.16 ( 0.44) | 2.13 ( 0.38) | 2.09 ( 0.32) | 2.05 ( 0.27) | 2.04 ( 0.23) | 2.00 ( 0.08) | 2.00 ( 0.02) | |
3.00 | (µ, σ) | (4.00, 8.33) | (2.35, 4.00) | (2.08, 2.58) | (2.03, 1.86) | (2.04, 1.55) | (2.07, 1.37) | (2.10, 1.24) | (2.12, 1.13) | (2.15, 1.04) | (2.17, 0.96) | (2.24, 0.75) | (2.29, 0.61) |
3 | 1.13 (0.35) | 1.75 (0.75) | 2.38 (0.92) | 2.64 (0.88) | 2.63 (0.76) | 2.58 (0.69) | 2.51 (0.61) | 2.49 (0.61) | 2.43 (0.54) | 2.40 (0.51) | 2.28 (0.45) | 2.16 (0.36) | |
5 | 1.02 (0.14) | 1.37 (0.51) | 1.88 (0.63) | 2.11 (0.62) | 2.11 (0.52) | 2.08 (0.43) | 2.05 (0.37) | 2.03 (0.32) | 2.01 (0.28) | 2.00 (0.23) | 1.99 (0.10) | 1.99 (0.05) | |
7 | 1.00 (0.06) | 1.18 (0.39) | 1.75 (0.54) | 1.84 (0.52) | 1.86 (0.46) | 1.85 (0.42) | 1.85 (0.38) | 1.85 (0.36) | 1.85 (0.35) | 1.85 (0.35) | 1.87 (0.33) | 1.87 (0.32) | |
4.00 | (µ, σ) | (5.12, 9.07) | (3.61, 5.53) | (3.15, 3.99) | (2.93, 2.81) | (2.86, 2.07) | (2.86, 1.68) | (2.88, 1.48) | (2.91, 1.35) | (2.94, 1.24) | (2.96, 1.15) | (3.04, 0.89) | (3.10, 0.73) |
3 | 1.10 (0.31) | 1.33 (0.54) | 1.61 (0.67) | 1.86 (0.71) | 1.97 (0.62) | 1.94 (0.71) | 1.94 (0.70) | 1.95 (0.40) | 1.95 (0.35) | 1.94 (0.32) | 1.96 (0.20) | 1.97 (0.17) | |
5 | 1.01 (0.11) | 1.10 (0.30) | 1.26 (0.45) | 1.50 (0.55) | 1.59 (0.53) | 1.59 (0.50) | 1.59 (0.49) | 1.58 (0.49) | 1.56 (0.49) | 1.55 (0.49) | 1.48 (0.49) | 1.42 (0.49) | |
7 | 1.00 (0.03) | 1.02 (0.15) | 1.05 (0.22) | 1.29 (0.46) | 1.34 (0.48) | 1.32 (0.46) | 1.29 (0.45) | 1.24 (0.43) | 1.20 (0.40) | 1.17 (0.37) | 1.07 (0.26) | 1.02 (0.15) | |