In production flowshop problems performance is often evaluat

In production flow-shop problems, performance is often evaluated by minimum make-span, the total elapsed time from starting the first job on the first machine until the last job is completed on the last machine. For a particular flow-shop the make-span was evaluated with respect to the number of jobs to be done. Let the independent variable X denote the number of jobs and the dependent variable Y denote the make-span (in standardized units):

Solution

Find Correlation .

r( X,Y) =    Co V ( X,Y) / S.D (X) * S.D (y)                  
r( X,Y) =    Sum(XY) / N- Mean of (X) * Mean of (Y) / Sqrt( X^2/n - ( Mean of X)^2 ) Sqrt( Y^2/n - ( Mean of Y)^2 )                    
                      
Co v ( X, Y ) =   1 /12 (1258.78) - [ 1/12 *114 ] [ 1/12 *115.03] =            13.833      
S. D ( X ) =   Sqrt( 1/12*1226-(1/12*114)^2)           3.452      
S .D (Y) =    Sqrt( 1/12*1302.9569-(1/12*115.03)^2)           4.086      
r(x,y) =    13.833 / 3.452*4.086   =   0.9807          

Set Up Hypothesis
Null, H0: =0
Alternate, H1: !=0
Test Statistic
Value of ( r ) =0.9807
Number (n)=12
we use Test Statistic (t) = r / Sqrt(1-r^2/(n-2))
to=0.9807/(Sqrt( ( 1-0.9807^2 )/(12-2) )
to =15.86
|to | =15.86
Critical Value
The Value of |t | at LOS 0.05% is 2.228
We got |to| =15.86 & | t | =2.228
Make Decision
Hence Value of | to | > | t | and Here we Reject Ho

Correlation
( X) ( Y) X^2 Y^2 X*Y
4 3.75 16 14.0625 15
5 4.9 25 24.01 24.5
6 4.88 36 23.8144 29.28
7 7.2 49 51.84 50.4
8 7.3 64 53.29 58.4
9 9.1 81 82.81 81.9
10 9 100 81 90
11 11.9 121 141.61 130.9
12 11.5 144 132.25 138
13 14.1 169 198.81 183.3
14 13.9 196 193.21 194.6
15 17.5 225 306.25 262.5
114 115.03 1226 1302.9569 1258.78 Totals
 In production flow-shop problems, performance is often evaluated by minimum make-span, the total elapsed time from starting the first job on the first machine

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