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.
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 –
Columns in a Control Plan
The following columns make up a typical control plan –
|Control PLan Column||Description|
|PART/PROCESS NUMBER||This is typically the process step number that matches both the process flow diagram and PFMEA|
|PROCESS NAME/DESCRIPTION||A clear description of each process step, i.e., “Drive screws 1 and 2”|
|MACHINE, DEVICE JIG, TOOLs FOR MFG||Devices 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 – NUMBER||This 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 – PRODUCT||If the characteristic being monitored is related to the product itself, fill in a brief description of the characteristic, i.e., “Screw torque”|
|CHARACTERISTICS – PROCESS||If 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 TOLERANCE||Note 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 TECHNIQUE||Note the method used for measuring the characteristic, i.e., “Digital Calipers”|
|SAMPLE SIZE||If 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 FREQUENCY||Note how many times per shift or hour a sample group is to be measured|
|CONTROL METHOD||Note the method by which process control is maintained, i.e., “Control Chart”|
|REACTION PLAN||Note how the associate is to react if a deviant condition is found|
While Excel control plans are very useful, more companies are moving to cloud-based collaboration tools for control plans. We took the above control plan and entered it into Monday.com in about 20 minutes. Here are some screenshots and comments.