Create Control Chart Setup

Explanation

Use this activity to set up Statistical Process Control (SPC) for a Control Plan line.

Prerequisites

• A control plan with at least one control plan line must exist. 
• The SPC check box for the control plan line must be selected.

System Effects

As a result of this activity, the control chart type is determined. Decisions are also made about how to calculate control limits for a specific Control Plan line, whether to include tolerance limits in the control chart, and whether one or many alarm rules should be activated.

Depending on the sample size that has been defined, the default settings for the Variable and Attribute SPC Setup will be changed.

Variable SPC Setup

• If the sample size has been defined as a percentage, only the X and MR Chart option will be available. The MR Sample size will be set to 3 as default. 

Attribute SPC Setup

• If the sample size has been defined as a fixed quantity, all the chart options will be available.
• If the sample size has been defined as a percentage, only the p chart and u chart options will be available. The Last N Subgroups and the Every K Subgroups control limit options will not be available. 
                   

Window

Control Plan - Manufacturing
Control Plan - Purchasing
Control Plan - Inventory

Related Window Descriptions

Control Plan - Manufacturing
Control Plan - Purchasing
Control Plan - Inventory
Variable SPC Setup
Variable SPC Setup/Control Limits
Variable SPC Setup/Alarm Rules
Attribute SPC Setup
Attribute SPC Setup/Control Limits
Attribute SPC Setup/Alarm Rules

Procedure

1. Select the Control Plan line.
2. Right-click and click Setup SPC Data.
3. Choose the control chart type. If the Control Plan line has the data type Variable, you can choose Xbar and R chart, Xbar and S chart, or X and MR chart. If the Control Plan line has the data type Attribute, you can choose an np, p, c, or u control chart.
4. If an X and MR chart has been chosen, enter the MR Sample Size.
5. Decide whether the tolerance limits should be displayed in the control chart.
6. Decide whether the sigma limits should be displayed in the control chart.
7. Steps eight through eleven are performed on the Control Limits tab.
8. Decide how to calculate the control limits. Choose between calculated or constant control limits.
9. If calculated control limits should be used, choose how the measurement data should be used in the calculations. You can choose between using All Data, Last N Subgroups, or Every K Subgroup. Enter the values for N and K, if appropriate.
10. If the Control Plan line has the data type Variable, you can also choose to calculate the control limits with constant values for the mean and standard deviation by entering values in the Mean and Std Dev fields.
11. If constant control limits should be used, enter values for the upper control limit (UCL), centerline (CL), and the lower control limit (LCL).
12. On the Alarm Rules tab, decide whether any alarm rules should be activated for this chart. The "Above Upper Control Limit" and "Below Lower Control Limit" alarm rules are activated by default but can be removed if necessary. If you click the Default Settings button, only these two rules will be activated.
13. Click Save Settings to activate the Control Chart setup.
14. Click Close to exit the Control Chart setup.