The student will be provided with a project scenario
via an Excel spreadsheet that will require the use of several analytical tools
to arrange, display and analyze data.
You are the Quality Manager for Widgets, Inc. You have just won a contract to produce a
specialized widget that the customer requires a very tight specification
limit. This widget is to be 5.50” in
length, plus or minus .50”. This gives
the total specification limit of 5.00” to 6.00”.
You have set up the production line to produce a test
run of the widgets (Data Set 1). The
sample size consists of a total of 20 samples per run, with a total of four (4)
runs. A total of 80 samples will be used
to determine if the process is capable of producing the widgets within
specification.
Due to the specifications of the customer, and the
setup of the manufacturing processes, the systematic random sampling technique
was used to ensure that samples from each run were collected at the same point
in time on different days. This provides
the basis for the X-bar chart to group the sample from each run into logical
subgroups.
Requirements:
1. Calculate the subgroup mean for each numbered sample
2. Calculate the grand mean and standard deviation of
the subgroup samples
3. Calculate the UCL and LCL of the grouped samples
4. Create the X-bar chart
5. Provide detailed analysis of the X-bar chart
To ensure that the process in actually producing
individual widgets within specification limits, you have decided to use an
Individual Measurement chart that will plot each of the 80 samples against a
calculated UCL and LCL, as well as plotting the data against the customer
specification limits.
Requirements:
1. Stack the sample data (place the run data into a
single column. Run 1 first, Run 2 second, etc)
2. Using the Data Analysis Toolpak, create the
Descriptive Statistics for the stacked data
3. Using the Descriptive Statistics output, calculate
the UCL and LCL
4. Create the IM chart using the calculated UCL and LCL
5. Recopy the stacked data, and enter the customer
specification limits
6. Create the IM chart of the sample data against the
customer specifications
7. Provide a detailed analysis of both IM charts
Answer the questions on the “Questions DS 1” tab on
the spreadsheet, and follow the instructions.
Repeat the steps for Data Set 2.
