【文章內(nèi)容簡(jiǎn)介】 Chart Using Minitab Commands Single response Stat Quality Tools MultiVari Chart Order of entry matters in this window. To arrange the plot in “standard” form, assign family 1 (panel to panel variation) to factor 1, the next larger time family to factor 2, the next larger time family to factor 3. Reserve factor 4 for a stream family like line. 28 In this example, all boxes should be unchecked to produce the first chart max length min length CTRL E or Stat Quality Tools MultiVari Chart Options Create a MultiVari Chart Using Minitab Commands 29 4 / 1 9 / 9 94 / 1 8 / 9 9PMAMPMAM0 . 0 50 . 0 40 . 0 30 . 0 20 . 0 50 . 0 40 . 0 30 . 0 212D a t e1 2 3 MultiV ari Chart for Film T hicknessF a ct o r 1 : Sa m p l e 。 F a ct o r 2 : A M / PM 。 F a ct o r 3 : D a t e 。 F a ct o r 4 : L I n eL i n e Sa m p l eChart Appearance Minitab plots the three samples in sequence left to right for line 1, 4/18/99 AM. The square shows the average of these three reading. The diamond is the average of all the readings within one day and line. 30 CrtlE or Stat Quality Tools MultiVari Charts… In the options window, connect the means for factors 13. Some people find it easier to see the relative contribution of the different families when the means are connected. Showing Changes in Average on the MultiVari Chart 31 4 / 1 8 / 9 9 4 / 1 9 / 9 9AMPMAMPM0 . 0 20 . 0 30 . 0 40 . 0 50 . 0 20 . 0 30 . 0 40 . 0 521D a t e1 2 3 F a ct o r 1 : Sa m p l e 。 F a ct o r 2 : A M / PM 。 F a ct o r 3 : D a t e 。 F a ct o r 4 : L i n eL i n e Sa m p l eMultiV ari Chart for Film T hickness?The vertical change in the lines connecting mean symbols shows the average contribution of the factor to the observed variation. ?The largest vertical change matches the dashed lines connecting the squares (the AM to PM variation). The smallest vertical change matches the dotted line connecting the diamonds (the day to day variation). Showing Changes in Average on the MultiVari Chart, cont. 32 Minitab FollowAlong, Part 2 Situation: An improvement team has narrowed down their attention to paint line 1. They are continuing their study of film thickness. Potential list of causes (abbreviated) ? Plant Ambient humidity ? Plant Ambient temperature ? Paintbooth temperature ? Paintbooth humidity ? Line pressure variation for pressors ? Paint viscosity ? Nozzle cleanliness ? Nozzle setting ? Surface contaminants (oxides) on the panels before painting ? Degrees Deviation from vertical (reference angle formed by nozzle tip and surface of panel) ? Temperature in the post paintbooth baking oven 33 Minitab FollowAlong, Part 2, cont. Main Work Step 1: Scope or domain of study ?A single production line in Plant X, on day shift only (paint line runs only on day shift, 6:30 to 2:30 .) Step 2: Time profile: ?Shortterm variation: consecutive units (three panels) ?Longerterm variation: morning and afternoon ?Longterm variation: Day to day, two days chosen to start. 34 Minitab FollowAlong, Part 2, cont. Step 3: a. Location of within unit samples Thickness of paint will be measured in center of front and back panel, as defined by template in QC lab and standard procedure. b. Number of measurements: ? Number of Observations within each unit (Family 1): Two, front and back. ? Number of Units: Three consecutive panels sampled at every bination of days and time of day (Family 2). ? Family 3: Longerterm variation (morning and afternoon)。 two levels, AM and PM. ? Family 4: Longterm variation (day to day)。 two levels: April 18 and April 19. 35 Minitab FollowAlong, Part 2, cont. 2 3 2 24 Days Levels Family 4 AM / PM Levels Family 3 2 Number of Consecutive Units (Family 2) Number of Observations Within Units (Family 1) Total measurements ? ? ? = 36 Minitab FollowAlong, Part 2, cont. Open file c:\BoosterData\ You should see these data in the worksheet: Panel ID Date AM/PM Position FilmThick True Time UnitName 1 4/18/99 AM Back 9:30 1 1 4/18/99 AM Front 9:30 1 2 4/18/99 AM Back 9:30 2 2 4/18/99 AM Front 9:30 2 3 4/18/99 AM Back 9:30 3 3 4/18/99 AM Front 9:30 3 4 4/18/99 PM Back 14:00 1 4 4/18/99 PM Front 14:00 1 5 4/18/99 PM Back 14:00 2 5 4/18/99 PM Front 14:00 2 6 4/18/99 PM Back 14:00 3 6 4/18/99 PM Front 14:00 3 7 4/19/99 AM Back 7:45 1 7 4/19/99 AM Front 7:45 1 8 4/19/99 AM Back 7:45 2 8 4/19/99 AM Front 7:45 2 9 4/19/99 AM Back 7:45 3 9 4/19/99 AM Front 7:45 3 10 4/19/99 PM Back 13:30 1 10 4/19/99 PM Front 13:30 1 11 4/19/99 PM Back 13:30 2 11 4/19/99 PM Front 13:30 2 12 4/19/99 PM Back 13:30 3 12 4/19/99 PM Front 13:30 3 37 Minitab FollowAlong, Part 2, cont. Step 6 Plot the sample data Stat Quality Tools MultiVari Chart First version of the multivari chart: Start with the the within unit family as factor 1。 here we select the two time families as factors 2 and 3 38 Minitab FollowAlong, Part 2, cont. Unless you check the first box, Minitab will only display the means of the f