The saying "an ounce of prevention is worth a pound of cure" is especially applicable when talking about prevention vs. detection in quality control. Estimates show that it is ten times more costly to correct a problem than it is to prevent one. Poor quality can result in additional business costs such as lost customers, wasted materials, product recalls, reworking the product, and cost of replacements and refunds.
But what is the best approach to ensuring product quality? It starts with understanding quality control and quality assurance.
What is Quality Control?
The concepts of quality control (QC) is best defined by the ISO 9001 guidance on developing a quality management system. QC falls under the category of "quality management.”
ISO 9001 defines quality control as "part of quality management centered on satisfying quality requirements." It is often contrasted with Quality Assurance which is defined as "part of quality management focused on providing confidence that quality requirements will be fulfilled." QC and QA may also encompass statistical quality control and statistical process control. Statistical quality control is the use of statistical methods to monitor and maintain the quality of products and services. In contrast, statistical process control (SPC) uses statistical techniques to evaluate and control a process or production method to minimize waste.
Quality assurance generally focuses on preventing defects. Quality control focuses on identifying defects.
The Problem with Relying on Detection in Quality Control
It is often helpful to consider the two dimensions of Quality Control - process and product testing. Process testing evaluates the conformity of critical-to-quality process elements such as machine parameters, water systems and other processing aids, raw materials, manufacturing materials, or utilities. Process testing has elements of both prevention and detection. Product testing evaluates the conformity of a process or finished goods. Product testing is essentially detection. An effective quality control program has an intentional balance of preventive and detective elements.
However, an over-reliance on detection elements can create a costly scenario with negative business impacts.
Detection by itself is insufficient
While product inspection to detect defects can be effective at improving outgoing quality levels, it is best to prevent those defects from occurring in the first place. Detection is never perfect. Until root causes of problems are identified and eliminated, defects will continue to be sent to customers, and your organization will forever be burdened with the ongoing management of quality problems.
Detection is expensive
In manufacturing processes, the detection of errors may require expensive equipment or additional personnel for inspections. Detection doesn't prevent the internal failure from recurring, but it can prevent it from reaching customers. Detection of a defect does not mean there are no costs incurred – in fact costs are added with each incremental step in the manufacturing process. Defective products add costs to your business and can substantially raise production costs.
Increases amount of scrap
Detection methods inevitably lead to scrapped materials, in-process or finished goods, and/or expensive rework. Every time you produce scrap or have to rework parts, you're increasing production costs associated with the corrective action.
Ineffective and inefficient methods for ensuring the quality of the products you supply to your customers can lead to customer complaints. Should you deliver defective items, expect increased customer complaints that can affect your profitability and impact your reputation. Manufacturing faulty products can also lead to costly product recalls or lawsuits. Management of complaints (documentation, investigation, corrective actions, CAPA) also add perpetual carrying costs.
The returns of defective products clause in supply agreements details the parties' specific obligations regarding defective products. Inadequate quality controls can lead to costly recalls and returns that impact your company's bottom line. By relying solely on detection, more customers may return defective products that do not meet that product's warranty conditions or specifications.
Costly root cause investigations
Detection of issues may ultimately trigger costly root cause investigations and CAPA actions. Following customer complaints and product returns and recalls, a systematic evaluation and analysis of the root cause of the non-conformance must be undertaken as required by the laws and regulations. CAPA actions are designed to identify and eliminate or rectify causes of non-conformities and other undesirable manufacturing situations. These investigations are not only time-consuming but can also be quite costly for your business.
Incorporating Prevention into Quality Control
Quality control has a role to play in the prevention (not just detection) of defects. When a problem is detected by quality control, there should be feedback to quality assurance. The feedback to quality assurance enables preventative measures to be put in place.
The preventive elements of quality control are generally more efficient and less costly than detection of defects that have already occurred. This is not a question of "prevention vs. detection" but instead a matter of "prevention and detection." Quality control and quality assurance are both needed for a quality management system (QMS) to function appropriately.
Work With Quality Experts
Robust quality assurance and quality control systems are critical to building a successful business that meets regulatory standards and customer's expectations.
If you build and sustain a prevention-oriented culture, both quality defects and non-conformances are driven out of the organization, and you will save on costs of re-makes and wastage.
However, incorporating prevention into your quality control process can be a daunting task, and it is best if you work with experts. Medpoint offers a global network of experts in quality control, quality assurance, and more generally quality management. For a no obligation consultation, contact us today.