Industry 4.0 and modern manufacturing activity are shaping up in such a manner that Quality and its management becomes an all-pervasive and value chain wide activity, to be pursued relentlessly.

Quality is a primary driver for customer satisfaction. Every aspect of manufacturing and supplying a product, from the time raw materials, parts or subassemblies are manufactured at a supply chain partner’s end, to the time they reach the end customer, quality and monitoring of relevant metrics is becoming vital.

With the advent and proliferation of big data, analytics, sensors and IoT, large amounts of data from all across the supply chain is available, and manufacturing pioneers are using this big data for driving process improvements and product innovation.

Given that Quality Management is critical to success in an Industry 4.0-enabled world, CAPA – Corrective and Preventive Actions, becomes an extremely crucial aspect of this hyper-connected and all-pervasive quality management environment. CAPA traditionally is an activity which deals with the occurrence of a non-conformity, whether it’s an out of spec product event during production, a machine breakdown, an equipment malfunction or any incident which affects the product’s quality or performance due to any reason. Corrective action is targeted at clearing the issue, so that the non-conformity detected ceases to exist and does not impact any future production lots/batches/product. It is followed by a root cause analysis which leads to a detailed understanding of the cause of the event so that procedures can be developed to identify and prevent the activity/action/event from re-occurring. When this whole activity is well defined, documented and strictly adhered to, it results in process improvement and thereby ensures that the Quality Management System in place is effective.

CAPA is critical for products that are regulated, and its oversight includes food and beverage products and medical devices. The FDA has published guidelines to ensure the correct procedures are being defined and implemented to uphold CAPA standards for medical devices, as part of their 21 CFR Part 820 regulations.

CAPA is split between two distinct but related functions:

  1. Corrective Action (CA), an extension of Root Cause Analysis (RCA). The first goal of CA is to find the root cause, base event or error that preceded the problem. The second goal is to take action directed at the root cause or error.
  2. Preventive Action (PA), similar to Lessons Learned. PA resembles the strategy of Design for Six Sigma (DFSS). The primary goal of PA is to inform an organization and prevent the problem from returning in other facilities lines or products.

CAPA started out as a manually performed activity with paper-based records being monitored and analyzed to detect issues. Post-detection would take significant time (hours at least, days at most) to devise corrective actions in the case of a novel type of error/issue. By the time the corrective action would actually be applied, numerous batches of product could have been affected until a root cause could be determined. If the issue detected was related to equipment rather than material, the impact of the quality incident might become quite widespread. Furthermore, by the time a preventive action was deployed, faulty product could have reached customers, forcing a recall, negatively impacting both the bottom line and the company’s brand value.

Of course, not all CAPA-related events lead to recalls or high costs. However, paper-based systems and manual management of CAPA always has a decision lag or a delay, as every event timeline, from detection to prevention of an issue, needs to be looked at by various process owners, discussed, debated, analyzed and then reported. Based on these reports, management would decide correct course of action; all of this means loss of time, which translates to loss of revenue and increased cost of product.

So while CAPA as an activity is essential for better overall production process management, improvement and control, the speed at which it’s executed and the ease in which decisions related to actions are taken have drastically evolved and improved. Modern CAPA management is a far more automated activity, which dramatically reduces the decision lag which existed in yesterdays’ paper-based systems.

In a digitized CAPA management system, actions and alarms are triggered automatically, and containment action may begin almost immediately once an event is detected. Intelligent analysis of contextualized data might reveal a root cause in a matter of minutes and suggested preventive actions can be taken. CAPA actions can cascade down the value chain with an integrated and Industry 4.0-ready IT network, saving time and ultimately, money.  

MES and CAPA

Now, in the modern world, where every aspect of the production process is measured, controlled and orchestrated by central applications like a MES/MOM platform, how and where does the CAPA process fit in? Does the MES-based CAPA restrict or enable the shop floor and management personnel to do their jobs better?

First, let’s understand where the CAPA module fits in an Industry 4.0-enabled value chain. Quality is pervasive, and for regulated industries, it’s an overarching requirement for each step of the transformation/production process to have oversight and governance.

MES or MOM platforms were first put in place to provide the governance of a highly complex discrete production process. The core functionality of most MES products includes Quality Management, so they are natural for integrating and enforcing the CAPA process.

As part of quality enforcement, CAPA actions will be triggered as soon as any process or product related non-conformity is detected. Depending upon the event and location of the breach, this may or may not apply to the supply chain partners, but most definitely applies to the manufacturing plant. Since the MES is the system which is responsible for collecting, analyzing and reporting data (both from the edge and from the process) CAPA needs to reside in the MES for it to be truly effective.

The CAPA activity itself is enhanced with the data collected and connectivity that a modern Industry 4.0 ready MES provides; it becomes far more automated, far more intelligent and moves towards prevention/prediction-based CAPA, not just event based CAPA.

What about NCRs?

NCR, or nonconformance requests, can be generated when a breach in the process or product occurs. Unlike a CAPA, an NCR is the front end notification.

The NCR serves 5 main purposes:

  1. It describes the non-conformity
  2. It determines the disposition of the non-conformity
  3. It tracks the non-conformity
  4. It assigns cost/s to the non-conformity
  5. It records approvals

The NCR then captures the non-conformity as well as recording the disposition. If you have to make a change to your process, or go through a root cause analysis, CAPA would then kick in.

Modern MES products fulfill both the NCR and CAPA functionality, which is critical for a modern Quality Management System for regulated products.

source: Critical Manufacturing

The MES, as the process oversight, captures, manages, and manipulates all production process and product related data. When an event is detected, the MES already has all historical data pertaining to all past events, as well as all process limits and specifications. It is able to prompt either an NCR or corrective action to floor personnel, eliminating any delay in implementation or containment action.

In highly automated plants, the MES might notify mandatory personnel either along with or after enforcing initial containment or corrective action. However, when the issue detected is new, the MES might suggest corrective actions, but the containment may remain automated as the containment methodology and cases may already be pre-determined and configured, which may range from re-routing of process to removal of a production lot/batch or triggering a maintenance call from in-house of third-party vendor.

Automated containment and corrective actions through the MES are quite literally the tip of the proverbial iceberg. The most interesting aspect is the way in which preventive action works in a modern MES and Industry 4.0 scenario.

New tools such as AR/VR, Big Data, Artificial Intelligence and Machine Learning can supplement the decision-making and analytics process. As the MES uses historical data and houses the SPC module, Machine Learning can be utilized to extract trends and uncover previously unknown data patterns; the intelligence created helps process owners structure preventive actions faster and more accurately pinpoint the weaknesses in the process or product design/production. These insights may go beyond simple preventive action, leading to process innovation.

As the process continues to improve, data continues to be monitored, root causes are found and eliminated and preventive actions aligned, the CAPA goes from a reactive to a proactive activity.

Based on ML fed data, the MES might prompt CAPA actions when trends indicate a potential failure, which means the whole cycle of containment, correction and prevention can be initiated even before an event can occur. This is where true value may be derived, and when this happens across multiple plants, or at factories of supply chain partners, the whole value chain raises benefits.

From a frontline worker standpoint, CAPA, when residing within the MES, boosts both worker knowledge and productivity. Modern MES applications automate notifications, alarms, and if allowed and configured might even take the initial containment and corrective action, even before plant personnel have the chance of reading a chart and realizing that an error or out of spec event has occurred.

Plant personnel can concentrate on their core activities and take actions needed to ensure CAPA is successfully implemented, rather than spending time in first recording, then analyzing and then finally reporting on breaches, before they even consider taking an action.

For management personnel, data from the floor is rationalized, presented in actionable forms (interactive charts, graphs) to facilitate analysis, and prompt the ‘right’ decisions, allowing them to focus on improvement efforts and work on eliminating detected root causes.

An MES with NCR and CAPA also incorporates ease of use, as it is the framework and infrastructure for CAPA activity. Modern MES applications allow plant personnel not only to review metrics they believe are essential, but they may also configure the modules the way they find most productive.

As an example, let’s consider that a seasoned operator through years of experience realizes that when a product of a particular spec is processed on a specific piece of equipment, the tension on a belt increases which has led to breakdowns in the past. With a modern MES and IoT data platform at their disposal, the operator using their knowledge might get a sensor installed to detect the tension on the belt. Though actual data gathered, they can not only prove their hypothesis, but even configure alarms for tension readings, prompt/define automated corrective actions and help determine a permanent preventive action.

For a modern knowledge worker, a CAPA which resides on the MES, offering configurability, Industry 4.0 technology and integrated functionality can accelerate internal knowledge, responsiveness, and quality management, resulting in an environment of continuous improvement.