Control Plans

A control plan lists all product and process inspection points required to deliver a defect-free outcome, and is essential for maintaining process control over the long run (related: control plan training PPT, control plan excel template).

While the control plan example on this page is manufacturing related, the same concept can be adapted to any number of physical or transactional work processes.

Here is a simple control plan for an assembly operation in a furniture manufacturing plant –

control plan example

Columns in a Control Plan

The following columns make up a typical control plan –

Control PLan ColumnDescription
PART/PROCESS NUMBERThis is typically the process step number that matches both the process flow diagram and PFMEA
PROCESS NAME/DESCRIPTIONA clear description of each process step, i.e., “Drive screws 1 and 2”
MACHINE, DEVICE JIG, TOOLs FOR MFGDevices and reference numbers (also noted on the devices themselves) for the major items needed to complete the task, i.e., “Electric screwdriver 987-01A1”
CHARACTERISTICS – NUMBERThis is a reference number for each characteristic being monitored. Control plans typically monitor product and process characteristics. For example, when manufacturing a disposable coffee cup, a product characteristic might be the overall height of the cup, and a process characteristic might be the curing temperature for the adhesive joining the top to the bottom of the cup.
CHARACTERISTICS – PRODUCTIf the characteristic being monitored is related to the product itself, fill in a brief description of the characteristic, i.e., “Screw torque”
CHARACTERISTICS – PROCESSIf the characteristic being monitored is related to the process, fill in a brief description of the characteristic, i.e., “Glue temperature.”
CTQ?Note “Yes” if the characteristic is a CTQ (Critical-to-Quality).
PRODUCT/PROCESS SPECIFICATION AND TOLERANCENote the specific product or process specification and tolerance for the characteristic being monitored, i.e., “Back-out screw torque between 26 and 29 in-lb”
EVALUATION/MEASUREMENT TECHNIQUENote the method used for measuring the characteristic, i.e., “Digital Calipers”
SAMPLE SIZEIf a random sample is drawn from production at some frequency, note the size of the sample. For example, a sample size of 5 is commonly used with some control charts. This is also referred to as the subgroup size in control charting.
SAMPLE FREQUENCYNote how many times per shift or hour a sample group is to be measured
CONTROL METHODNote the method by which process control is maintained, i.e., “Control Chart”
REACTION PLANNote how the associate is to react if a deviant condition is found