3.5.2.4. Throughput

3. Production Process Characterization
3.5. Case Studies
3.5.2. Machine Screw Case Study

3.5.2.4. Throughput

The throughput is summarized in the following table (this was part of the original data collection, not the result of analysis).

Machine	Day 1	Day 2	Day 3
1	576	604	583
2	657	604	586
3	510	546	571

This table shows that machine 3 had significantly lower throughput.

Graphical Representation of Throughput

We can show the throughput graphically.

The graph clearly shows the lower throughput for machine 3.

Analysis of Variance for Throughput

We can confirm the statistical significance of the lower throughput of machine 3 by running an analysis of variance.

  
                 **********************************
                 **********************************
                 **  1-WAY ANALYSIS OF VARIANCE  **
                 **********************************
                 **********************************
  
       NUMBER OF OBSERVATIONS           =        9
       NUMBER OF FACTORS                =        1
       NUMBER OF LEVELS FOR FACTOR  1  =        3
       BALANCED CASE
       RESIDUAL    STANDARD DEVIATION   =    0.28953985214E+02
       RESIDUAL    DEGREES OF FREEDOM   =        6
       REPLICATION CASE
       REPLICATION STANDARD DEVIATION   =    0.28953985214E+02
       REPLICATION DEGREES OF FREEDOM   =        6
       NUMBER OF DISTINCT CELLS         =        3
  
                          *****************
                          *  ANOVA TABLE  *
                          *****************
  
 SOURCE              DF SUM OF SQUARES    MEAN SQUARE   F STATISTIC    F CDF SIG
 -------------------------------------------------------------------------------
 TOTAL (CORRECTED)    8   13246.888672    1655.861084
 -------------------------------------------------------------------------------
 FACTOR  1            2    8216.898438    4108.449219        4.9007  94.525%
 -------------------------------------------------------------------------------
 RESIDUAL             6    5030.000000     838.333313
  
       RESIDUAL    STANDARD DEVIATION =       28.95398521423
       RESIDUAL    DEGREES OF FREEDOM =             6
       REPLICATION STANDARD DEVIATION =       28.95398521423
       REPLICATION DEGREES OF FREEDOM =             6

                          ****************
                          *  ESTIMATION  *
                          ****************
  
       GRAND MEAN                       =    0.58188891602E+03
       GRAND STANDARD DEVIATION         =    0.40692272186E+02
  
  
              LEVEL-ID      NI      MEAN      EFFECT     SD(EFFECT)
 --------------------------------------------------------------------
 FACTOR 1--    1.00000      3.  587.66669    5.77777   13.64904
         --    2.00000      3.  615.66669   33.77777   13.64904
         --    3.00000      3.  542.33331  -39.55560   13.64904
  
  
         MODEL               RESIDUAL STANDARD DEVIATION
 -------------------------------------------------------
 CONSTANT             ONLY--       40.6922721863
 CONSTANT & FACTOR  1 ONLY--       28.9539852142

Interpretation of ANOVA Output

We summarize the effect estimates in the following table.

Means for Oneway Anova
Level Number Mean Standard Error Lower 95% CI Upper 95% CI

1 3 587.667 16.717 546.76 628.57

2 3 615.667 16.717 574.76 656.57

3 3 542.33 16.717 501.43 583.24

The Dataplot macro file shows the computations required to go from the Dataplot ANOVA output to the numbers in the above table.