CAQ – Computer-aided Quality Assurance


Computer-aided quality assurance (CAQ) refers to a subarea of quality management that uses digital technologies to optimize production processes. The main focus is on improving production quality and customer satisfaction. By consolidating and evaluating data, CAQ systems create a basis for adjusting work processes in a targeted manner.

CAQ – Quality Assurance in Industry 4.0

The abbreviation CAQ stands for computer-aided quality assurance. This refers to measures in Industry 4.0 that support a company's quality management through the use of EDP systems. By evaluating measurement data, it is possible to determine performance indicators (KPI) that enable the targeted optimization of workflows with regard to the efficient prevention of failures. In addition, a CAQ system fulfills tasks in document management and archiving of data. It thus creates a basis for forecasts and adjustments to the quality strategy. CAQ is based on standards such as DIN EN ISO 9001, which defines guidelines for quality management as well as industry-specific regulations and the company's internal quality standards.

Tasks and areas of application of CAQ systems

CAQ records all quality-relevant steps of the value chain from the preparation of production and material procurement to the completion and possible processing of returns:

  • At goods receipt it is already checked whether materials required for production are delivered in full and in perfect quality. This provides the basis for systematic supplier evaluation.
  • Advanced Product Quality Planning (APQP) sets standards to be expected from the finished product even before production begins. In this way, compliance with them can be tracked as the manufacturing process progresses.
  • The machine capability test provides information on the reject and rework rate with which a production step can be carried out on a given machine. In addition, an initial sample test provides information on whether the product can be manufactured without defects under realistic conditions.
  • During production, a CAQ system enables statistical process control, which ensures the most uniform production quality possible.
  • Regular and scheduled audits ensure that problems and deficiencies in the manufacturing process are detected and eliminated at an early stage.
  • The failure mode and effects analysis (FMEA) allows estimates to be made of how frequently product defects occur or are discovered and what risk they pose to the fault-free functioning of the product (and thus to the end consumer).
  • Competent complaint management based on the 8D process or a comparable concept enables customer satisfaction to be maintained in the event of a defective product. The use of a CAQ system also makes processes in returns management traceable, allowing employees to draw conclusions about the causes of frequent defects.

Benefits of a CAQ system

In this way, a CAQ system makes it possible to detect potential sources of error even before production begins. In this way, realistic standards can be determined for series production. Furthermore, the continuous compliance with quality standards and norms in production can be checked in this way. Measures can thus be taken in the event of negative developments. However, computer-aided quality assurance is not a static process. Rather, the entire manufacturing process is continuously optimized through constant analysis of work steps and accompanying processes in order to produce high-quality products as cost-effectively as possible. This is made possible by visualizing information on production steps in the form of graphics, key figures and reports. These make the current status and the effectiveness of adjustments quantifiable.

System, Modules and Functions - The Anatomy of CAQ Systems

In general, the term "CAQ system" refers to the entire IT infrastructure used for quality assurance. This infrastructure consists of several networked modules, each of which supports one application unit. This can be, for example, a step of the production process, a department of the company or a cross-sectional task such as the analysis of measurement data. This measurement data provides functions of the system. A function in the context of CAQ is a single quality management activity performed by a program. For example, a module that monitors the condition of a particular machine would contain functions that record measurement data and create inspection and maintenance plans.

The Modular Structure of a CAQ System

Since CAQ systems must be adapted to the needs of the company in which they are used, their structure is usually modular. Depending on requirements, additional modules can be connected to a central information module and exchange data with it and with each other.

It is also possible to connect overarching modules, for example, for managing workflows and complaints and for managing documents. In this way, a system is created that networks all quality-relevant areas of the company and provides them with the information they need to ensure quality standards and customer satisfaction.

Central measure management

The data from all other modules converge in the measures management module. In this way, decision-makers are able to obtain an overview of the current status of production processes and make adjustments.

Goods receipt and supplier management

A module for managing incoming goods records data on incoming deliveries and compliance with deadlines, as well as qualitative information on incoming goods. In this way, objective supplier evaluations can be carried out, which provide a decision-making basis for the further purchasing strategy.

Production management

MES modules monitor the production process as such. To this end, they collect data on capacity utilization, scrap rates and process efficiency, among other things, as well as any anomalies in the production process. This makes it possible to uncover sources of error and inefficient production steps and to respond effectively to production events.

Production inspection

For random testing of manufacturing quality, a manufacturing inspection module creates inspection plans and provides support for testing products and documenting the results. This makes it possible to check whether the finished product meets the company's quality standards before series production begins.


Frequently Asked Questions (FAQ) about computer-aided quality assurance

What does a CAQ system do?

A CAQ system records all quality-related steps in the value chain, from preparation of production and material procurement to completion and possible processing of returns. It also performs document management and data archiving tasks.

How exactly does a CAQ system support decision makers in process optimization?

When using stand-alone solutions, a large amount of data accumulates in proprietary formats. These cannot be evaluated by other software; optimization is difficult. A CAQ system, on the other hand, is designed for this exchange from the start. Its modular structure makes it possible to add additional components so that all quality-relevant data is available and can be evaluated in a single system.

What is the difference between CAQ and MES?

Manufacturing Execution Software (MES) is the term used to describe systems that enable the optimization of manufacturing processes based on production data. In contrast to CAQ systems, however, the focus is exclusively on the production process as such. Other quality-relevant influencing factors such as procurement or the management of complaints are not taken into account. Accordingly, MES should be seen as a supplement to, but not a competitor of, a CAQ system.

What is the 8D Process?

The 8D process (also: 8D report) can be understood as a standardized form of information exchange between customer and manufacturer in the event of a complaint. In this way, a complaint passes through eight process steps (disciplines) from the occurrence of a problem to its resolution. Due to its complexity, however, this form of problem solving is only worthwhile in the case of complex defects. Likewise, it is only applicable if the item complained about was functioning until the defect occurred.

How do machine capability and process capability differ?

While machine capability refers to the pure defect rate of a process on a machine, process capability refers to a quantifiable characteristic of the finished product. Thus, machine capability provides a basis for deciding whether the machine can meet the quality requirements of the manufacturing process. Process capability, on the other hand, is a measure of quality capability that looks at a deviation from normal.

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