PAPER CUTTING EXECISE [The following is a message from Grant Blair on an exercise he developed. The exercise is offered here with his permission. If you want to provide feedback or ask questions, you can find his address at the end of the text.] Appreciate the feedback, and I hope the explanation I am sending will provide the detail you need to run the Paper-Cutting demonstration successfully...In order to avoid a Split, I am going to provide the detail in 4 parts: Part 1: How to construct the Measuring and Cutting Template Part 2: How to demonstrate Common Cause Variation Part 3: How to Demonstrate Special Cause Variation Part 4: Process Improvement & Developing a control chart Part 1 Follows: Preparing the Measuring Template: Starting from the bottom of an 8 « by 11 piece of paper: Step 1: Scribe across the paper every « inch (There should be 21 lines) Step 2: Number the lines up the Page as follows: 15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,0,-1,-2,-3,-4,-5 Preparing the Cutting Templates: Using yellow construction paper create the following: Number as: Size: 1 3 « inches 2 4 inches 3 4 « inches 4 5 inches 5 5 « inches 6 6 inches Give these to the participants. Using blue construction paper create the following: Number as: Size: -5 « inch -4 1 inch -3 1 « inches -2 2 inches -1 2 « inches 0 3 inches 7 6 « inches 8 7 inches ..........through 15 10 « inches The instructor will keep these and only hand them out if needed. Part 2- Paper-Cutting Without Adjustment Designate one person as a worker, and provide him with: cutting templates 1-6, scissors, die, pencil, and 20 sheets of paper. Use a second person as an inspector, and provide him with the measuring template. (You could also designate someone as a machine, and let him roll the die). Procedure will be to roll the die and use the face number to select a cutting template to mark and cut the paper. The part of the sheet of paper covered by the template will be discarded, and the remainder will be passed to the inspector. Stress the importance of placing a dot on the piece passed in order to avoid mistakes. Point out, (either now or later) that this is what Deming meant by Written procedures and training. Show the blue templates to the class and indicate they are available if needed. Produce about 20 sheets of paper and create a histogram. Determine the rounded average (3 or 4) This will be used in the next exercise. Example: 3,2,4,4,3,5,1,4,1,1,1,6,4,1,4,4,5,1,6 Part 3- Paper-Cutting With Adjustment Designate an additional person as an engineer to calculate a machine adjustment for producing the next piece. Instead of selecting the template from the dice, the worker will add the adjustment to the face value to select the cutting template. This is a good time to introduce the concept of negative numbers and use a numberline centered at 3 (or 4) to let the class visualize the adjustment. Once again, show the blue templates and indicate they are available if needed. Usually, the process will go out of control well before 20 pieces are made. This exercise illustrates the most common type of overcontrol in a plant environment, and production workers usually see it quickly. Using the same data as an example: Dice + Adj.= Use Template # Calculate next adjustment 3= ........................... 3....................3-3=0 2 + 0=............................2....................3-2=+1 4 +1=.............................5....................3-5= -2 4 +(-2)=..........................2....................3-2=+1 3+1=..............................4....................3-4= -1 5+(-1)=...........................4....................3-4= -1 1+(-1)=.......................... 0................... 3-0=+3 4+3=............................. 7................... 3-7= -4 1+(-4)=......................... -3................... 3-(-3)=+6 1+6=..............................7................... 3-7= -4 1+(-4)=......................... -3................... 3-(-3)=+6 6+6=............................ 12................... 3-12= -9 4+(-9)=..........................-5................... 3+(-5)=+8 1+8=............................. 9................... 3-9= -6 4+(-6)=......................... -2....................3-(-2)=+5 4+5=..............................9................... 3-9= -6 5+(-6)=......................... -1................... 3-(-1)=+4 1+4=..............................5....................3-5= -2 6+(-2)=...........................4................... 3-4= -1 2+(-1)=.......................... 1........................ Stop Finally, plot the histogram and compare it against the first one. Part 4- Special Cause Variation: Provide the team with a stack of legal paper (8 « x 14). When the worker notices the paper is longer, ask him." What is your job title? (Answer s, "worker"!) Use this to illustrate Deming's Point #8...Creating trust in workforce. Now check out the reason for the longer paper, and report that Purchasing has made a "real deal" on this paper. Encourage the worker to "make this work". This illustrates Point #4...awarding business on price tag only. Once you have a couple of readings, calculate an adjustment as you did in the second exercise and show that a single target adjustment would bring the process in line. Next, provide a team with an 8-sided die and show that adjustment won't work (or you can shuffle the regular and legal paper together. Improving the Process: Although a coin will work, I use poker chips: The first one has 3 on one side and 4 on the other; The second one has 3 on both sides. Emphasize that Common Cause must be improved by Management. Special Cause by the Workforce. Control Chart Finally we develop a control chart for this process using averages and ranges (Subgroups of 4 ). Logically, the upper control limit is set at 6, the lower limit at 1, with a UCL on the Range Chart of 5. I provide a set of data, and we calculate and plot the chart. We also plot a histogram of the averages and develop the properties of the Normal Distribution to introduce the Central Limit Theorem. grantblair@aol.com or call, Grant Blair, 319 Port Royal Drive Ninety-Six SC 29666 803-543-4052