Statistical Process Control

Unit Overview
Measuring and Means
Quality Assurance
Data Collection
Credits




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Statistical Process Control

Activity 3 (Student Copy)
Collecting and Interpreting Data

Materials

  • coil samples
  • rulers (cm)
  • calculators (one per group of four students)
  • Reference Sheet R3

  1. For each coil sample, on Reference Sheet R3 list the number that identifies the sample in the "date" space (since the date and time categories are unnecessary for this activity). Measure each set of five coils, recording their lengths, mean length, and longest and shortest coil lengths (record all measurements to the nearest tenth of a centimeter). Graph the sample means as you work through different samples. (Note that the control limits used are unrealistic and have been expanded, for the purposes of this activity, beyond that which would be acceptable to the coil company and customer.)

  2. Using Reference Sheet R2, name any patterns that you see on your graph and state any action that is required. Circle and label these patterns on your graph.

    "Run Rule" Situation Noted Action Required (if any)


  3. Why do you think each of the following categories of information is recorded for each sample?

    date and time:


    individual coil lengths:


    mean coil length:



    longest and shortest coil lengths:


  4. Were there any "bad parts" in your samples (i.e., individual coils that fell outside of the specified acceptable range for length)?



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Area 10 Mathematics and Technology Professional Development Center
Permission is granted to duplicate these materials for classroom use.

Last updated on 1/30/1999
Comments: egalindo@indiana.edu
http://www.indiana.edu/~atmat/units/spc/proc_s3.htm