Production and Process Controls – Thinking About Quality

By Michael Biros
April 7, 2014


• Categories: 04-Product Design & Development

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An effective quality system takes a total systems approach to satisfy safety, effectiveness, and performance requirements. Quality should be considered at all stages of production, starting at the earliest stages of product design.

To ensure that finished devices will be safe and effective, current Good Manufacturing Practice (cGMP) requirements govern the facilities and controls used for the design, manufacture, packaging, labeling, storage, installation, and servicing of all medical devices. A recent Medical Device Summit Quality System Regulation webinar, featured Dr. Vinny Sastri, President of Winovia LLC, who highlighted some of the key elements of effective production and process controls. We present some excerpts below.

Sources of variation

Effective design factors in sources of variation in production such as product specifications, process parameters, raw materials, equipment, test methods, etc. and aims to reduce the variation so that the product’s safety, quality, and effectiveness remains consistent through the entire production process. 

Critical inputs to critical outputs

Quantifiable relationships of critical inputs to critical outputs should guide the process development. Critical quality inputs define process parameters and control the incoming materials and components. Critical quality outputs measure how the product specifications and capability are being met. Critical quality outputs guide sampling plans and acceptance criteria which control the production process.

Quality function deployment

Quality Function Deployment (QFD) is a method that can be used to identify critical parameters that affect product specifications. Customer requirements determine product performance specifications which determine component specifications in the product design and how production processes are controlled. This method is used primarily for critical to quality analysis. Critical to safety analysis calls for methods that use risk assessment and management.

Levels of control

Determining the criticality of input parameters (quality and control of processes and components) and essential outputs (safety, effectiveness, and quality of the product) can help determine the levels of control that are needed during production. Some tools that can help identify and manage risk are: Preliminary Hazard Analysis (PHA), Risk Analysis, Fault Tree Analysis (FTA), Failure Modes and Effects Analysis (FMEA), and Hazard Analysis and Critical Control Points (HACCP).

Testing methods

After a product has gone through the design process and production, it goes through testing. The acceptance criteria and testing results should be used to make decisions. The testing methods should be suitable, reliable, and validated. Testing should be able to detect changes, measure/quantify performance, and detect impurities. It is important to use appropriate testing methods and to have low measurement error. If the product passes a test, but fails in true performance, then there’s a major risk to the end user that is not being quantified. However, if the product fails a test, but performs fine in the marketplace, then there is a business risk in losing money by not having the right product go out. 

Process validation

Process validation consists of Installation, Operational, and Performance Qualification. Installation Qualification (IQ) determines if the equipment is installed and operating according to specifications. Operational Qualification (OQ) determines if the process is fully characterized and if there are critical process parameters established. Performance Qualification (PQ) determines if the process, when run under optimal conditions, produces a result that consistently meets specifications. It is important to identify a statically valid number of lots that will definite the capability and consistency of the product. Software as part of production equipment and quality systems, all equipment, buildings, facilities, utilities, and cleaning methods should all be validated. 

Know the entire process

From supplier control for incoming raw materials to storage, distribution, installation, and servicing, the entire process should be monitored and controlled. Mapping the entire process allows identifying and controlling the process and acceptance criteria across the process lifetime. Document all steps in the process and be sure to create instructions, SOPs, and training regimens. Monitoring and control of process parameters allows long-term analysis of production data which can ensure safe, effective, and consistent devices; growth and profitability for business; and compliance with regulations and standards.