What are the criteria for process control?

Process controls are used to control both sample treatment and test procedure and should therefore ideally be included at the beginning of the actual sample treatment. However, in on-line sampling, or sampling directly from tap in an outbreak situation, it is not possible to add controls before sampling. Instead, they may be added after sample elution.

 

• How to select a process control system?

• Requirements for effective process control

 

How to select a process control system?

Selecting a process control system (PCS) involves experienced personnel and understanding critical elements for operations. The process control system (PCS) ties all the automation elements of a process manufacturing unit together and affects every aspect of operations. As the brain and central nervous system of a facility, its performance level and quality are crucial to keep operations running smoothly.

 

As new technology is introduced in the automation and control industry, now is the perfect time for manufacturers to modernize a process control system (PCS) platform to improve efficiency and operational performance. They can innovate—not duplicate—the functionality of the existing legacy infrastructure. However, manufacturers must carefully select the PCS and a third-party vendor who understands their specific platform requirements that can optimize and upgrade their facility.

 

Requirements for effective process control

Clear Product Specifications: clear product specifications clarify for the factory operator exactly how to use the product specifications in the acceptance, rejection or rework of the product.

Valid and Capable Metrology: valid and capable metrology assures the measurement instrument(s) and measurement process we are using to control the process is fit for use and well controlled. Every gage needs to be profiled to make sure it is fit for use.

Characterization: characterization of the process allows the engineer to determine precisely which process factors affect the product, their relative magnitude and numerical

sensitivity. A subset of the process factors must be selected for process control.

Sample Plan：the process sample plan defines where to take process measurements, how

many to take, and the frequency. This is often referred to as rational subgroup formation.

Control Chart Development: based on the data from the sample plan the correct control chart needs to be selected such that the process control rules will properly detect out of control conditions. If the correct control chart is not selected the control system will have

too many charts, or it will not correctly flag out of control conditions.

Out of Control Action Plan (OCAP): the OCAP is written to provide the process operator detailed guidelines for process adjustment. They are written to be specific to the control rule violated.

Documentation: all of the process, metrology and process control procedures need to be

documented to assure standardization of the process.

Training: all of the people in the process need to make sure they have a common understanding and language concerning the process and process control systems and the detailed procedures for controlling and adjusting the process. The training program provides the theories and practical knowledge for process control system design and implementation.

Database: the database is primarily designed for Engineering and Customer use. It stores

the process and product information and provides a simple and powerful interface to summarize and analyze performance.

Periodic Audits: periodic audits are designed to sustain the improvements in the control system. They provide management feedback that the floor controls are carefully followed

and corrective action if they are not adhered to.

 

Process control is used in continuous production – in manufacturing and in other fields and industries where some kind of material is produced without any kind of interruption – as well as in “batch processing.” It’s used to automatically control the conditions in which a product is made – ensuring better quality and efficiency. Juson Automation Company is dedicated to process control and will provide you with high quality process control service. If you have any problems, please feel free to contact us.