Control plans list the product and process characteristics monitored during the manufacturing process, including measurement methods and necessary reaction plans for deviant conditions. Control plans come in a variety of formats, and the most popular is the Excel format found in our downloads page.
While control plans generally do not improve product quality, they play the important role of sustaining product quality long after a manufacturing process is developed and launched. Without control plans, most processes will gradually drift into a state of disrepair due to employee turnover, knowledge loss, and short-term production priorities.
What Makes an Effective Control Plan?
1. Clear Product Specifications
Product specifications are clearly defined and linked to customer requirements.
A PFMEA (Process Failure Modes and Effects Analysis) has been conducted on all process steps, and the team fully understands the quality risks associated with each step.
3. Effective Measurement Methods and Reaction Plans
Process and product measurement methods must be clearly defined and repeatable.
4. A Quality System
An over-arching quality system ensures that new associates are trained in following control plans, and that all aspects supporting gaging, etc. are properly maintained.
The Real Key to Process Control
Preventing defects at the point of origin is the most efficient form of process control. This is known as error proofing, which means that a defective condition cannot be created in the first place. One example is the larger diameter nozzle found on diesel pumps, which will not fit into a standard size gas tank opening. In this case, the defect of putting the wrong gas in the car cannot occur to begin with. Another error-proofing example is a conveyor curing oven that will stop automatically and sound an alarm if the oven temperature falls outside a predefined window. In this case, the defective condition of an uncured product cannot occur because the oven stops and an alarm sounds before uncured product can be produced.